28638371464 has 32 divisors (see below), whose sum is σ = 53976608280. Its totient is φ = 14244757504.

The previous prime is 28638371459. The next prime is 28638371473. The reversal of 28638371464 is 46417383682.

It can be written as a sum of positive squares in 4 ways, for example, as 25843134564 + 2795236900 = 160758^2 + 52870^2 .

It is a super-2 number, since 2×28638371464² (a number of 22 digits) contains 22 as substring.

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, 1629894 + ... + 1647370.

Almost surely, 2^28638371464 is an apocalyptic number.

It is an amenable number.

28638371464 is a deficient number, since it is larger than the sum of its proper divisors (25338236816).

28638371464 is a wasteful number, since it uses less digits than its factorization.

28638371464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18537 (or 18533 counting only the distinct ones).

The product of its digits is 4644864, while the sum is 52.

The spelling of 28638371464 in words is "twenty-eight billion, six hundred thirty-eight million, three hundred seventy-one thousand, four hundred sixty-four".