21658138434 has 48 divisors (see below), whose sum is σ = 48038582592. Its totient is φ = 7048357344.

The previous prime is 21658138423. The next prime is 21658138451. The reversal of 21658138434 is 43483185612.

21658138434 is a `hidden beast` number, since 2 + 1 + 6 + 581 + 38 + 4 + 34 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21658138434.

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, 2283987 + ... + 2293449.

It is an arithmetic number, because the mean of its divisors is an integer number (1000803804).

Almost surely, 2^21658138434 is an apocalyptic number.

21658138434 is an abundant number, since it is smaller than the sum of its proper divisors (26380444158).

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

21658138434 is a wasteful number, since it uses less digits than its factorization.

21658138434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12471 (or 12468 counting only the distinct ones).

The product of its digits is 552960, while the sum is 45.

The spelling of 21658138434 in words is "twenty-one billion, six hundred fifty-eight million, one hundred thirty-eight thousand, four hundred thirty-four".