21064960 has 72 divisors (see below), whose sum is σ = 57689856. Its totient is φ = 7219200.

The previous prime is 21064957. The next prime is 21064993. The reversal of 21064960 is 6946012.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

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, 7785 + ... + 10135.

It is an arithmetic number, because the mean of its divisors is an integer number (801248).

Almost surely, 2^21064960 is an apocalyptic number.

21064960 is a gapful number since it is divisible by the number (20) 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 21064960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28844928).

21064960 is an abundant number, since it is smaller than the sum of its proper divisors (36624896).

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

21064960 is an equidigital number, since it uses as much as digits as its factorization.

21064960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2379 (or 2365 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 21064960 is about 4589.6579393240. The cubic root of 21064960 is about 276.1766005524.

The spelling of 21064960 in words is "twenty-one million, sixty-four thousand, nine hundred sixty".