23385571721 has 4 divisors (see below), whose sum is σ = 23386804752. Its totient is φ = 23384338692.

The previous prime is 23385571717. The next prime is 23385571753. The reversal of 23385571721 is 12717558332.

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 not a de Polignac number, because 23385571721 - 2² = 23385571717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (23385571771) 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, 587615 + ... + 626148.

It is an arithmetic number, because the mean of its divisors is an integer number (5846701188).

Almost surely, 2^23385571721 is an apocalyptic number.

It is an amenable number.

23385571721 is a deficient number, since it is larger than the sum of its proper divisors (1233031).

23385571721 is a wasteful number, since it uses less digits than its factorization.

23385571721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1233030.

The product of its digits is 352800, while the sum is 44.

The spelling of 23385571721 in words is "twenty-three billion, three hundred eighty-five million, five hundred seventy-one thousand, seven hundred twenty-one".