21662005172 has 12 divisors (see below), whose sum is σ = 37916716740. Its totient is φ = 10828657536.

The previous prime is 21662005171. The next prime is 21662005307. The reversal of 21662005172 is 27150026612.

It can be written as a sum of positive squares in 2 ways, for example, as 4900560016 + 16761445156 = 70004^2 + 129466^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21662005171) 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, 565397 + ... + 602492.

It is an arithmetic number, because the mean of its divisors is an integer number (3159726395).

Almost surely, 2^21662005172 is an apocalyptic number.

It is an amenable number.

21662005172 is a deficient number, since it is larger than the sum of its proper divisors (16254711568).

21662005172 is a wasteful number, since it uses less digits than its factorization.

21662005172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1172530 (or 1172528 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 32.

The spelling of 21662005172 in words is "twenty-one billion, six hundred sixty-two million, five thousand, one hundred seventy-two".