Search a number
-
+
121221021 = 340407007
BaseRepresentation
bin1110011100110…
…10111110011101
322110002122222110
413032122332131
5222013033041
620010104233
73001235025
oct716327635
9273078873
10121221021
1162476169
123471b079
131c16391c
1412156a85
15a997516
hex739af9d

121221021 has 4 divisors (see below), whose sum is σ = 161628032. Its totient is φ = 80814012.

The previous prime is 121221019. The next prime is 121221029. The reversal of 121221021 is 120122121.

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.

It is not a de Polignac number, because 121221021 - 21 = 121221019 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 121220988 and 121221006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121221029) 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, 20203501 + ... + 20203506.

It is an arithmetic number, because the mean of its divisors is an integer number (40407008).

Almost surely, 2121221021 is an apocalyptic number.

It is an amenable number.

121221021 is a deficient number, since it is larger than the sum of its proper divisors (40407011).

121221021 is an equidigital number, since it uses as much as digits as its factorization.

121221021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40407010.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 121221021 is about 11010.0418255336. The cubic root of 121221021 is about 494.9097151937.

Adding to 121221021 its reverse (120122121), we get a palindrome (241343142).

It can be divided in two parts, 1212 and 21021, that multiplied together give a palindrome (25477452).

The spelling of 121221021 in words is "one hundred twenty-one million, two hundred twenty-one thousand, twenty-one".

Divisors: 1 3 40407007 121221021