21357832 has 8 divisors (see below), whose sum is σ = 40045950. Its totient is φ = 10678912.

The previous prime is 21357827. The next prime is 21357857. The reversal of 21357832 is 23875312.

It can be written as a sum of positive squares in only one way, i.e., 13883076 + 7474756 = 3726^2 + 2734^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 21357794 and 21357803.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1334857 + ... + 1334872.

Almost surely, 2^21357832 is an apocalyptic number.

It is an amenable number.

21357832 is a deficient number, since it is larger than the sum of its proper divisors (18688118).

21357832 is a wasteful number, since it uses less digits than its factorization.

21357832 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2669735 (or 2669731 counting only the distinct ones).

The product of its digits is 10080, while the sum is 31.

The square root of 21357832 is about 4621.4534510260. The cubic root of 21357832 is about 277.4506342941.

The spelling of 21357832 in words is "twenty-one million, three hundred fifty-seven thousand, eight hundred thirty-two".