21170536 has 16 divisors (see below), whose sum is σ = 39744900. Its totient is φ = 10571904.

The previous prime is 21170533. The next prime is 21170537. The reversal of 21170536 is 63507112.

It can be written as a sum of positive squares in 2 ways, for example, as 20520900 + 649636 = 4530^2 + 806^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21170536.

It is not an unprimeable number, because it can be changed into a prime (21170533) 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, 9286 + ... + 11338.

Almost surely, 2^21170536 is an apocalyptic number.

It is an amenable number.

21170536 is a deficient number, since it is larger than the sum of its proper divisors (18574364).

21170536 is a wasteful number, since it uses less digits than its factorization.

21170536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3348 (or 3344 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 21170536 is about 4601.1450748700. The cubic root of 21170536 is about 276.6372240083.

Adding to 21170536 its reverse (63507112), we get a palindrome (84677648).

The spelling of 21170536 in words is "twenty-one million, one hundred seventy thousand, five hundred thirty-six".