23121736421 has 4 divisors (see below), whose sum is σ = 26424841632. Its totient is φ = 19818631212.

The previous prime is 23121736403. The next prime is 23121736441. The reversal of 23121736421 is 12463712132.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-23121736421 is a prime.

It is a super-2 number, since 2×23121736421² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23121736441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1651552595 + ... + 1651552608.

It is an arithmetic number, because the mean of its divisors is an integer number (6606210408).

Almost surely, 2^23121736421 is an apocalyptic number.

It is an amenable number.

23121736421 is a deficient number, since it is larger than the sum of its proper divisors (3303105211).

23121736421 is an equidigital number, since it uses as much as digits as its factorization.

23121736421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3303105210.

The product of its digits is 12096, while the sum is 32.

The spelling of 23121736421 in words is "twenty-three billion, one hundred twenty-one million, seven hundred thirty-six thousand, four hundred twenty-one".