90731 has 2 divisors, whose sum is σ = 90732.
Its totient is φ = 90730.
The previous prime is 90709. The next prime is 90749. The reversal of 90731 is 13709.
It is a strong prime.
It is an emirp because it is prime and its reverse (13709) is a distict prime.
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-90731 is a prime.
It is a super-2 number, since 2×907312 = 16464228722, which contains 22 as substring.
It is a Chen prime.
It is an Ulam number.
It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 90731.
It is not a weakly prime, because it can be changed into another prime (90031) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45365 + 45366.
It is an arithmetic number, because the mean of its divisors is an integer number (45366).
290731 is an apocalyptic number.
90731 is a deficient number, since it is larger than the sum of its proper divisors (1).
90731 is an equidigital number, since it uses as much as digits as its factorization.
90731 is an odious number, because the sum of its binary digits is odd.
The product of its (nonzero) digits is 189, while the sum is 20.
The square root of 90731 is about 301.2158694359.
The cubic root of 90731 is about 44.9350503345.
The spelling of 90731 in words is "ninety thousand, seven hundred thirty-one".