23575820921 has 4 divisors (see below), whose sum is σ = 23576619252. Its totient is φ = 23575022592.

The previous prime is 23575820857. The next prime is 23575820929. The reversal of 23575820921 is 12902857532.

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 17486359696 + 6089461225 = 132236^2 + 78035^2 .

It is a cyclic number.

It is not a de Polignac number, because 23575820921 - 2⁶ = 23575820857 is a prime.

It is a super-2 number, since 2×23575820921² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (23575820929) 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, 353096 + ... + 414521.

It is an arithmetic number, because the mean of its divisors is an integer number (5894154813).

Almost surely, 2^23575820921 is an apocalyptic number.

It is an amenable number.

23575820921 is a deficient number, since it is larger than the sum of its proper divisors (798331).

23575820921 is an equidigital number, since it uses as much as digits as its factorization.

23575820921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 798330.

The product of its (nonzero) digits is 302400, while the sum is 44.

The spelling of 23575820921 in words is "twenty-three billion, five hundred seventy-five million, eight hundred twenty thousand, nine hundred twenty-one".