21257874018 has 48 divisors (see below), whose sum is σ = 46870734456. Its totient is φ = 6961317120.

The previous prime is 21257874007. The next prime is 21257874041. The reversal of 21257874018 is 81047875212.

21257874018 is a `hidden beast` number, since 2 + 1 + 2 + 578 + 74 + 0 + 1 + 8 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1157156289 + 20100717729 = 34017^2 + 141777^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 925246 + ... + 947942.

Almost surely, 2^21257874018 is an apocalyptic number.

21257874018 is an abundant number, since it is smaller than the sum of its proper divisors (25612860438).

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

21257874018 is a wasteful number, since it uses less digits than its factorization.

21257874018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23619 (or 23616 counting only the distinct ones).

The product of its (nonzero) digits is 250880, while the sum is 45.

The spelling of 21257874018 in words is "twenty-one billion, two hundred fifty-seven million, eight hundred seventy-four thousand, eighteen".