21630676 has 6 divisors (see below), whose sum is σ = 37853690. Its totient is φ = 10815336.

The previous prime is 21630659. The next prime is 21630689. The reversal of 21630676 is 67603612.

It can be written as a sum of positive squares in only one way, i.e., 12082576 + 9548100 = 3476^2 + 3090^2 .

It is a super-2 number, since 2×21630676² = 935772288433952, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2703831 + ... + 2703838.

Almost surely, 2^21630676 is an apocalyptic number.

It is an amenable number.

21630676 is a deficient number, since it is larger than the sum of its proper divisors (16223014).

21630676 is a wasteful number, since it uses less digits than its factorization.

21630676 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5407673 (or 5407671 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 31.

The square root of 21630676 is about 4650.8790566946. The cubic root of 21630676 is about 278.6271059683.

The spelling of 21630676 in words is "twenty-one million, six hundred thirty thousand, six hundred seventy-six".