21772755165 has 64 divisors (see below), whose sum is σ = 40632883200. Its totient is φ = 9749963520.

The previous prime is 21772755163. The next prime is 21772755181. The reversal of 21772755165 is 56155727712.

It is not a de Polignac number, because 21772755165 - 2¹ = 21772755163 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21772755163) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1264786 + ... + 1281884.

It is an arithmetic number, because the mean of its divisors is an integer number (634888800).

Almost surely, 2^21772755165 is an apocalyptic number.

It is an amenable number.

21772755165 is a deficient number, since it is larger than the sum of its proper divisors (18860128035).

21772755165 is a wasteful number, since it uses less digits than its factorization.

21772755165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17362.

The product of its digits is 1029000, while the sum is 48.

The spelling of 21772755165 in words is "twenty-one billion, seven hundred seventy-two million, seven hundred fifty-five thousand, one hundred sixty-five".