28578731 has 2 divisors, whose sum is σ = 28578732. Its totient is φ = 28578730.

The previous prime is 28578721. The next prime is 28578749. The reversal of 28578731 is 13787582.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28578731 - 2²² = 24384427 is a prime.

It is a super-2 number, since 2×28578731² = 1633487731140722, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28578721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14289365 + 14289366.

It is an arithmetic number, because the mean of its divisors is an integer number (14289366).

Almost surely, 2^28578731 is an apocalyptic number.

28578731 is a deficient number, since it is larger than the sum of its proper divisors (1).

28578731 is an equidigital number, since it uses as much as digits as its factorization.

28578731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 94080, while the sum is 41.

The square root of 28578731 is about 5345.9078742530. The cubic root of 28578731 is about 305.7367515381.

The spelling of 28578731 in words is "twenty-eight million, five hundred seventy-eight thousand, seven hundred thirty-one".