90728731 has 2 divisors, whose sum is σ = 90728732. Its totient is φ = 90728730.

The previous prime is 90728681. The next prime is 90728783. The reversal of 90728731 is 13782709.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-90728731 is a prime.

It is a super-2 number, since 2×90728731² = 16463405257740722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (90720731) 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, 45364365 + 45364366.

It is an arithmetic number, because the mean of its divisors is an integer number (45364366).

Almost surely, 2^90728731 is an apocalyptic number.

90728731 is a deficient number, since it is larger than the sum of its proper divisors (1).

90728731 is an equidigital number, since it uses as much as digits as its factorization.

90728731 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21168, while the sum is 37.

The square root of 90728731 is about 9525.1630432240. The cubic root of 90728731 is about 449.3467575293.

The spelling of 90728731 in words is "ninety million, seven hundred twenty-eight thousand, seven hundred thirty-one".