28957531 has 2 divisors, whose sum is σ = 28957532. Its totient is φ = 28957530.

The previous prime is 28957471. The next prime is 28957541. The reversal of 28957531 is 13575982.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28957531 - 2⁷ = 28957403 is a prime.

It is a super-2 number, since 2×28957531² = 1677077203231922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (28957541) 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 as a sum of consecutive naturals, namely, 14478765 + 14478766.

It is an arithmetic number, because the mean of its divisors is an integer number (14478766).

Almost surely, 2^28957531 is an apocalyptic number.

28957531 is a deficient number, since it is larger than the sum of its proper divisors (1).

28957531 is an equidigital number, since it uses as much as digits as its factorization.

28957531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 75600, while the sum is 40.

The square root of 28957531 is about 5381.2202147840. The cubic root of 28957531 is about 307.0816343295.

The spelling of 28957531 in words is "twenty-eight million, nine hundred fifty-seven thousand, five hundred thirty-one".