23212420021 has 4 divisors (see below), whose sum is σ = 26528480032. Its totient is φ = 19896360012.

The previous prime is 23212420001. The next prime is 23212420043. The reversal of 23212420021 is 12002421232.

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-23212420021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23212420001) 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, 1658029995 + ... + 1658030008.

It is an arithmetic number, because the mean of its divisors is an integer number (6632120008).

Almost surely, 2^23212420021 is an apocalyptic number.

It is an amenable number.

23212420021 is a deficient number, since it is larger than the sum of its proper divisors (3316060011).

23212420021 is an equidigital number, since it uses as much as digits as its factorization.

23212420021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3316060010.

The product of its (nonzero) digits is 384, while the sum is 19.

Adding to 23212420021 its reverse (12002421232), we get a palindrome (35214841253).

The spelling of 23212420021 in words is "twenty-three billion, two hundred twelve million, four hundred twenty thousand, twenty-one".