21707040388 has 18 divisors (see below), whose sum is σ = 41754659198. Its totient is φ = 9866836320.

The previous prime is 21707040367. The next prime is 21707040391. The reversal of 21707040388 is 88304070712.

It can be written as a sum of positive squares in only one way, i.e., 14940661824 + 6766378564 = 122232^2 + 82258^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21707040388.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 22424145 + ... + 22425112.

Almost surely, 2^21707040388 is an apocalyptic number.

It is an amenable number.

21707040388 is a deficient number, since it is larger than the sum of its proper divisors (20047618810).

21707040388 is a wasteful number, since it uses less digits than its factorization.

21707040388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44849283 (or 44849270 counting only the distinct ones).

The product of its (nonzero) digits is 75264, while the sum is 40.

The spelling of 21707040388 in words is "twenty-one billion, seven hundred seven million, forty thousand, three hundred eighty-eight".