21755574164 has 24 divisors (see below), whose sum is σ = 38189589480. Its totient is φ = 10844312576.

The previous prime is 21755574157. The next prime is 21755574187. The reversal of 21755574164 is 46147555712.

It can be written as a sum of positive squares in 4 ways, for example, as 17516522500 + 4239051664 = 132350^2 + 65108^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1983704 + ... + 1994640.

It is an arithmetic number, because the mean of its divisors is an integer number (1591232895).

Almost surely, 2^21755574164 is an apocalyptic number.

It is an amenable number.

21755574164 is a deficient number, since it is larger than the sum of its proper divisors (16434015316).

21755574164 is a wasteful number, since it uses less digits than its factorization.

21755574164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12427 (or 12425 counting only the distinct ones).

The product of its digits is 1176000, while the sum is 47.

The spelling of 21755574164 in words is "twenty-one billion, seven hundred fifty-five million, five hundred seventy-four thousand, one hundred sixty-four".