21534786 has 48 divisors (see below), whose sum is σ = 57430464. Its totient is φ = 5679072.

The previous prime is 21534763. The next prime is 21534827. The reversal of 21534786 is 68743512.

It is a self number, because there is not a number n which added to its sum of digits gives 21534786.

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, 4936 + ... + 8211.

It is an arithmetic number, because the mean of its divisors is an integer number (1196468).

Almost surely, 2^21534786 is an apocalyptic number.

21534786 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21534786 is an abundant number, since it is smaller than the sum of its proper divisors (35895678).

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

21534786 is a wasteful number, since it uses less digits than its factorization.

21534786 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13175 (or 13172 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 21534786 is about 4640.5588025582. The cubic root of 21534786 is about 278.2147728717.

The spelling of 21534786 in words is "twenty-one million, five hundred thirty-four thousand, seven hundred eighty-six".