21957044 has 6 divisors (see below), whose sum is σ = 38424834. Its totient is φ = 10978520.

The previous prime is 21957043. The next prime is 21957049. The reversal of 21957044 is 44075912.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 18490000 + 3467044 = 4300^2 + 1862^2 .

It is a super-2 number, since 2×21957044² = 964223562435872, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21957044.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21957043) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2744627 + ... + 2744634.

It is an arithmetic number, because the mean of its divisors is an integer number (6404139).

Almost surely, 2^21957044 is an apocalyptic number.

It is an amenable number.

21957044 is a deficient number, since it is larger than the sum of its proper divisors (16467790).

21957044 is a wasteful number, since it uses less digits than its factorization.

21957044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5489265 (or 5489263 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 21957044 is about 4685.8343974153. The cubic root of 21957044 is about 280.0214439359.

The spelling of 21957044 in words is "twenty-one million, nine hundred fifty-seven thousand, forty-four".