2172651864 has 48 divisors (see below), whose sum is σ = 5612555160. Its totient is φ = 700848000.

The previous prime is 2172651863. The next prime is 2172651883. The reversal of 2172651864 is 4681562712.

It is a happy number.

It is a super-2 number, since 2×2172651864² = 9440832244285348992, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2172651863) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 24037 + ... + 70164.

Almost surely, 2^2172651864 is an apocalyptic number.

2172651864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

2172651864 is an abundant number, since it is smaller than the sum of its proper divisors (3439903296).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2172651864 is a wasteful number, since it uses less digits than its factorization.

2172651864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94272 (or 94237 counting only the distinct ones).

The product of its digits is 161280, while the sum is 42.

The square root of 2172651864 is about 46611.7138067246. The cubic root of 2172651864 is about 1295.1797555119.

The spelling of 2172651864 in words is "two billion, one hundred seventy-two million, six hundred fifty-one thousand, eight hundred sixty-four".