28931577 has 8 divisors (see below), whose sum is σ = 39119040. Its totient is φ = 19015920.

The previous prime is 28931557. The next prime is 28931593. The reversal of 28931577 is 77513982.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-28931577 is a prime.

It is a super-2 number, since 2×28931577² = 1674072295413858, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28931537) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 67702 + ... + 68127.

It is an arithmetic number, because the mean of its divisors is an integer number (4889880).

Almost surely, 2^28931577 is an apocalyptic number.

It is an amenable number.

28931577 is a deficient number, since it is larger than the sum of its proper divisors (10187463).

28931577 is a wasteful number, since it uses less digits than its factorization.

28931577 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135903.

The product of its digits is 105840, while the sum is 42.

The square root of 28931577 is about 5378.8081393558. The cubic root of 28931577 is about 306.9898633951.

The spelling of 28931577 in words is "twenty-eight million, nine hundred thirty-one thousand, five hundred seventy-seven".