28718731 has 2 divisors, whose sum is σ = 28718732. Its totient is φ = 28718730.

The previous prime is 28718717. The next prime is 28718749. The reversal of 28718731 is 13781782.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28718731 - 2⁵ = 28718699 is a prime.

It is a super-2 number, since 2×28718731² = 1649531020500722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (28718231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14359365 + 14359366.

It is an arithmetic number, because the mean of its divisors is an integer number (14359366).

Almost surely, 2^28718731 is an apocalyptic number.

28718731 is a deficient number, since it is larger than the sum of its proper divisors (1).

28718731 is an equidigital number, since it uses as much as digits as its factorization.

28718731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18816, while the sum is 37.

The square root of 28718731 is about 5358.9860048334. The cubic root of 28718731 is about 306.2351809572.

The spelling of 28718731 in words is "twenty-eight million, seven hundred eighteen thousand, seven hundred thirty-one".