21976144 has 20 divisors (see below), whose sum is σ = 42972820. Its totient is φ = 10886400.

The previous prime is 21976111. The next prime is 21976153. The reversal of 21976144 is 44167912.

It can be written as a sum of positive squares in 2 ways, for example, as 11478544 + 10497600 = 3388^2 + 3240^2 .

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, 4557 + ... + 8044.

It is an arithmetic number, because the mean of its divisors is an integer number (2148641).

Almost surely, 2^21976144 is an apocalyptic number.

It is an amenable number.

21976144 is a deficient number, since it is larger than the sum of its proper divisors (20996676).

21976144 is a wasteful number, since it uses less digits than its factorization.

21976144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12718 (or 12712 counting only the distinct ones).

The product of its digits is 12096, while the sum is 34.

The square root of 21976144 is about 4687.8720119048. The cubic root of 21976144 is about 280.1026154497.

The spelling of 21976144 in words is "twenty-one million, nine hundred seventy-six thousand, one hundred forty-four".