28912257 has 48 divisors (see below), whose sum is σ = 49533120. Its totient is φ = 16051200.

The previous prime is 28912249. The next prime is 28912277. The reversal of 28912257 is 75221982.

It is not a de Polignac number, because 28912257 - 2³ = 28912249 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28912277) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 68794 + ... + 69212.

It is an arithmetic number, because the mean of its divisors is an integer number (1031940).

Almost surely, 2^28912257 is an apocalyptic number.

It is an amenable number.

28912257 is a deficient number, since it is larger than the sum of its proper divisors (20620863).

28912257 is a wasteful number, since it uses less digits than its factorization.

28912257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 494 (or 491 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

The square root of 28912257 is about 5377.0119025347. The cubic root of 28912257 is about 306.9215140287.

The spelling of 28912257 in words is "twenty-eight million, nine hundred twelve thousand, two hundred fifty-seven".