21757136 has 20 divisors (see below), whose sum is σ = 42951492. Its totient is φ = 10672896.

The previous prime is 21757123. The next prime is 21757157. The reversal of 21757136 is 63175712.

It can be written as a sum of positive squares in 2 ways, for example, as 11155600 + 10601536 = 3340^2 + 3256^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11981 + ... + 13676.

Almost surely, 2^21757136 is an apocalyptic number.

It is an amenable number.

21757136 is a deficient number, since it is larger than the sum of its proper divisors (21194356).

21757136 is a wasteful number, since it uses less digits than its factorization.

21757136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25718 (or 25712 counting only the distinct ones).

The product of its digits is 8820, while the sum is 32.

The square root of 21757136 is about 4664.4545233071. The cubic root of 21757136 is about 279.1690329445.

The spelling of 21757136 in words is "twenty-one million, seven hundred fifty-seven thousand, one hundred thirty-six".