21342864 has 40 divisors (see below), whose sum is σ = 55900192. Its totient is φ = 7015680.

The previous prime is 21342857. The next prime is 21342883. The reversal of 21342864 is 46824312.

It is a nude number because it is divisible by every one of its digits.

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, 459 + ... + 6549.

Almost surely, 2^21342864 is an apocalyptic number.

21342864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21342864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27950096).

21342864 is an abundant number, since it is smaller than the sum of its proper divisors (34557328).

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

21342864 is a wasteful number, since it uses less digits than its factorization.

21342864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6175 (or 6169 counting only the distinct ones).

The product of its digits is 9216, while the sum is 30.

The square root of 21342864 is about 4619.8337632430. The cubic root of 21342864 is about 277.3858048112.

The spelling of 21342864 in words is "twenty-one million, three hundred forty-two thousand, eight hundred sixty-four".