28920815 has 24 divisors (see below), whose sum is σ = 43602720. Its totient is φ = 18025920.

The previous prime is 28920809. The next prime is 28920833. The reversal of 28920815 is 51802982.

It is not a de Polignac number, because 28920815 - 2²² = 24726511 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 821 + ... + 7649.

It is an arithmetic number, because the mean of its divisors is an integer number (1816780).

Almost surely, 2^28920815 is an apocalyptic number.

28920815 is a deficient number, since it is larger than the sum of its proper divisors (14681905).

28920815 is a wasteful number, since it uses less digits than its factorization.

28920815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6863 (or 6852 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 35.

The square root of 28920815 is about 5377.8076388060. The cubic root of 28920815 is about 306.9517938647.

The spelling of 28920815 in words is "twenty-eight million, nine hundred twenty thousand, eight hundred fifteen".