21682864 has 20 divisors (see below), whose sum is σ = 48012304. Its totient is φ = 9292608.

The previous prime is 21682861. The next prime is 21682897. The reversal of 21682864 is 46828612.

It is not an unprimeable number, because it can be changed into a prime (21682861) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96687 + ... + 96910.

Almost surely, 2^21682864 is an apocalyptic number.

It is an amenable number.

21682864 is an abundant number, since it is smaller than the sum of its proper divisors (26329440).

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

21682864 is a wasteful number, since it uses less digits than its factorization.

21682864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193612 (or 193606 counting only the distinct ones).

The product of its digits is 36864, while the sum is 37.

The square root of 21682864 is about 4656.4862289069. The cubic root of 21682864 is about 278.8510057789.

The spelling of 21682864 in words is "twenty-one million, six hundred eighty-two thousand, eight hundred sixty-four".