21310944 has 24 divisors (see below), whose sum is σ = 55941480. Its totient is φ = 7103616.

The previous prime is 21310937. The next prime is 21310957. The reversal of 21310944 is 44901312.

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×21310944² = 908312668342272, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 110899 + ... + 111090.

It is an arithmetic number, because the mean of its divisors is an integer number (2330895).

Almost surely, 2^21310944 is an apocalyptic number.

21310944 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21310944 is an abundant number, since it is smaller than the sum of its proper divisors (34630536).

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

21310944 is a wasteful number, since it uses less digits than its factorization.

21310944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222002 (or 221994 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 21310944 is about 4616.3778008304. The cubic root of 21310944 is about 277.2474514238.

The spelling of 21310944 in words is "twenty-one million, three hundred ten thousand, nine hundred forty-four".