21339264 has 64 divisors (see below), whose sum is σ = 57674880. Its totient is φ = 6988800.

The previous prime is 21339247. The next prime is 21339277. The reversal of 21339264 is 46293312.

21339264 is nontrivially palindromic in base 14.

It is a tau number, because it is divible by the number of its divisors (64).

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, 22969 + ... + 23879.

It is an arithmetic number, because the mean of its divisors is an integer number (901170).

Almost surely, 2^21339264 is an apocalyptic number.

21339264 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 21339264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28837440).

21339264 is an abundant number, since it is smaller than the sum of its proper divisors (36335616).

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

21339264 is an equidigital number, since it uses as much as digits as its factorization.

21339264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 989 (or 977 counting only the distinct ones).

The product of its digits is 7776, while the sum is 30.

The square root of 21339264 is about 4619.4441224026. Note that the first 3 decimals coincide. The cubic root of 21339264 is about 277.3702079503.

The spelling of 21339264 in words is "twenty-one million, three hundred thirty-nine thousand, two hundred sixty-four".