21032516 has 12 divisors (see below), whose sum is σ = 36875580. Its totient is φ = 10496640.

The previous prime is 21032513. The next prime is 21032521. The reversal of 21032516 is 61523012.

It can be written as a sum of positive squares in 2 ways, for example, as 13764100 + 7268416 = 3710^2 + 2696^2 .

It is not an unprimeable number, because it can be changed into a prime (21032513) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2345 + ... + 6896.

It is an arithmetic number, because the mean of its divisors is an integer number (3072965).

Almost surely, 2^21032516 is an apocalyptic number.

It is an amenable number.

21032516 is a deficient number, since it is larger than the sum of its proper divisors (15843064).

21032516 is a wasteful number, since it uses less digits than its factorization.

21032516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9814 (or 9812 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 21032516 is about 4586.1221091462. The cubic root of 21032516 is about 276.0347397286.

Adding to 21032516 its reverse (61523012), we get a palindrome (82555528).

It can be divided in two parts, 210 and 32516, that multiplied together give a triangular number (6828360 = T₃₆₉₅).

The spelling of 21032516 in words is "twenty-one million, thirty-two thousand, five hundred sixteen".