121121000021 has 4 divisors (see below), whose sum is σ = 138424000032. Its totient is φ = 103818000012.

The previous prime is 121120999999. The next prime is 121121000089. The reversal of 121121000021 is 120000121121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 120000121121 = 71 ⋅1690142551.

It is a cyclic number.

It is not a de Polignac number, because 121121000021 - 2³⁴ = 103941130837 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121120999966 and 121121000011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121121000321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8651499995 + ... + 8651500008.

It is an arithmetic number, because the mean of its divisors is an integer number (34606000008).

Almost surely, 2^121121000021 is an apocalyptic number.

It is an amenable number.

121121000021 is a deficient number, since it is larger than the sum of its proper divisors (17303000011).

121121000021 is an equidigital number, since it uses as much as digits as its factorization.

121121000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17303000010.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 121121000021 its reverse (120000121121), we get a palindrome (241121121142).

The spelling of 121121000021 in words is "one hundred twenty-one billion, one hundred twenty-one million, twenty-one", and thus it is an aban number.