21286528 has 16 divisors (see below), whose sum is σ = 42407010. Its totient is φ = 10643200.

The previous prime is 21286513. The next prime is 21286537. The reversal of 21286528 is 82568212.

It can be written as a sum of positive squares in only one way, i.e., 20866624 + 419904 = 4568^2 + 648^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is a junction number, because it is equal to n+sod(n) for n = 21286493 and 21286502.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83023 + ... + 83278.

Almost surely, 2^21286528 is an apocalyptic number.

It is an amenable number.

21286528 is a deficient number, since it is larger than the sum of its proper divisors (21120482).

21286528 is an equidigital number, since it uses as much as digits as its factorization.

21286528 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166315 (or 166303 counting only the distinct ones).

The product of its digits is 15360, while the sum is 34.

The square root of 21286528 is about 4613.7325453476. The cubic root of 21286528 is about 277.1415299371.

The spelling of 21286528 in words is "twenty-one million, two hundred eighty-six thousand, five hundred twenty-eight".