28640646 has 24 divisors (see below), whose sum is σ = 62169120. Its totient is φ = 9529296.

The previous prime is 28640639. The next prime is 28640653. The reversal of 28640646 is 64604682.

It is a happy number.

28640646 is a `hidden beast` number, since 2 + 8 + 6 + 4 + 0 + 646 = 666.

It is an interprime number because it is at equal distance from previous prime (28640639) and next prime (28640653).

It is a self number, because there is not a number n which added to its sum of digits gives 28640646.

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 in 11 ways as a sum of consecutive naturals, for example, 11836 + ... + 14048.

It is an arithmetic number, because the mean of its divisors is an integer number (2590380).

Almost surely, 2^28640646 is an apocalyptic number.

28640646 is an abundant number, since it is smaller than the sum of its proper divisors (33528474).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28640646 is a wasteful number, since it uses less digits than its factorization.

28640646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2940 (or 2937 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

The square root of 28640646 is about 5351.6956191473. The cubic root of 28640646 is about 305.9573822488.

The spelling of 28640646 in words is "twenty-eight million, six hundred forty thousand, six hundred forty-six".