28663690 has 24 divisors (see below), whose sum is σ = 56713860. Its totient is φ = 10422720.

The previous prime is 28663673. The next prime is 28663709. The reversal of 28663690 is 9636682.

It can be written as a sum of positive squares in 2 ways, for example, as 24611521 + 4052169 = 4961^2 + 2013^2 .

It is a super-2 number, since 2×28663690² = 1643214248832200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10635 + ... + 13054.

Almost surely, 2^28663690 is an apocalyptic number.

28663690 is a deficient number, since it is larger than the sum of its proper divisors (28050170).

28663690 is a wasteful number, since it uses less digits than its factorization.

28663690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23718 (or 23707 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 40.

The square root of 28663690 is about 5353.8481487618. The cubic root of 28663690 is about 306.0394170819.

It can be divided in two parts, 2866 and 3690, that added together give a palindrome (6556).

The spelling of 28663690 in words is "twenty-eight million, six hundred sixty-three thousand, six hundred ninety".