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121000021 = 346134961
BaseRepresentation
bin1110011011001…
…01000001010101
322102200102211021
413031211001111
5221434000041
620001241141
72666324512
oct715450125
9272612737
10121000021
116233511a
12346331b1
131c0b715c
14120da309
15a951cd1
hex7365055

121000021 has 4 divisors (see below), whose sum is σ = 121038444. Its totient is φ = 120961600.

The previous prime is 121000003. The next prime is 121000049. The reversal of 121000021 is 120000121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 35640900 + 85359121 = 5970^2 + 9239^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2k-121000021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 120999968 and 121000013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121000421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14020 + ... + 20941.

It is an arithmetic number, because the mean of its divisors is an integer number (30259611).

Almost surely, 2121000021 is an apocalyptic number.

It is an amenable number.

121000021 is a deficient number, since it is larger than the sum of its proper divisors (38423).

121000021 is an equidigital number, since it uses as much as digits as its factorization.

121000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38422.

The product of its (nonzero) digits is 4, while the sum is 7.

The square root of 121000021 is about 11000.0009545454. Note that the first 3 decimals coincide. The cubic root of 121000021 is about 494.6087729386.

Adding to 121000021 its reverse (120000121), we get a palindrome (241000142).

The spelling of 121000021 in words is "one hundred twenty-one million, twenty-one", and thus it is an aban number.

Divisors: 1 3461 34961 121000021