21357044 has 6 divisors (see below), whose sum is σ = 37374834. Its totient is φ = 10678520.

The previous prime is 21357043. The next prime is 21357053. The reversal of 21357044 is 44075312.

It can be written as a sum of positive squares in only one way, i.e., 19254544 + 2102500 = 4388^2 + 1450^2 .

It is a super-2 number, since 2×21357044² = 912246656835872, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21357043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2669627 + ... + 2669634.

It is an arithmetic number, because the mean of its divisors is an integer number (6229139).

Almost surely, 2^21357044 is an apocalyptic number.

It is an amenable number.

21357044 is a deficient number, since it is larger than the sum of its proper divisors (16017790).

21357044 is a wasteful number, since it uses less digits than its factorization.

21357044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5339265 (or 5339263 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 26.

The square root of 21357044 is about 4621.3681956754. The cubic root of 21357044 is about 277.4472220597.

The spelling of 21357044 in words is "twenty-one million, three hundred fifty-seven thousand, forty-four".