21152764 has 12 divisors (see below), whose sum is σ = 37067800. Its totient is φ = 10561968.

The previous prime is 21152759. The next prime is 21152783. The reversal of 21152764 is 46725112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 127 + ... + 6505.

Almost surely, 2^21152764 is an apocalyptic number.

It is an amenable number.

21152764 is a deficient number, since it is larger than the sum of its proper divisors (15915036).

21152764 is a wasteful number, since it uses less digits than its factorization.

21152764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7212 (or 7210 counting only the distinct ones).

The product of its digits is 3360, while the sum is 28.

The square root of 21152764 is about 4599.2134110085. The cubic root of 21152764 is about 276.5597929172.

Adding to 21152764 its reverse (46725112), we get a palindrome (67877876).

It can be divided in two parts, 211 and 52764, that added together give a triangular number (52975 = T₃₂₅).

The spelling of 21152764 in words is "twenty-one million, one hundred fifty-two thousand, seven hundred sixty-four".