21052684 has 24 divisors (see below), whose sum is σ = 38931200. Its totient is φ = 9933840.

The previous prime is 21052679. The next prime is 21052687. The reversal of 21052684 is 48625012.

It is not an unprimeable number, because it can be changed into a prime (21052687) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33049 + ... + 33679.

Almost surely, 2^21052684 is an apocalyptic number.

It is an amenable number.

21052684 is a deficient number, since it is larger than the sum of its proper divisors (17878516).

21052684 is a wasteful number, since it uses less digits than its factorization.

21052684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1093 (or 1091 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 21052684 is about 4588.3203898595. The cubic root of 21052684 is about 276.1229410984.

Adding to 21052684 its reverse (48625012), we get a palindrome (69677696).

It can be divided in two parts, 21052 and 684, that added together give a triangular number (21736 = T₂₀₈).

The spelling of 21052684 in words is "twenty-one million, fifty-two thousand, six hundred eighty-four".