90308531 has 2 divisors, whose sum is σ = 90308532. Its totient is φ = 90308530.

The previous prime is 90308509. The next prime is 90308591. The reversal of 90308531 is 13580309.

It is a weak prime.

It is an emirp because it is prime and its reverse (13580309) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-90308531 is a prime.

It is a super-2 number, since 2×90308531² = 16311261542755922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 90308494 and 90308503.

It is not a weakly prime, because it can be changed into another prime (90308591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45154265 + 45154266.

It is an arithmetic number, because the mean of its divisors is an integer number (45154266).

Almost surely, 2^90308531 is an apocalyptic number.

90308531 is a deficient number, since it is larger than the sum of its proper divisors (1).

90308531 is an equidigital number, since it uses as much as digits as its factorization.

90308531 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 90308531 is about 9503.0800796373. The cubic root of 90308531 is about 448.6519840346.

The spelling of 90308531 in words is "ninety million, three hundred eight thousand, five hundred thirty-one".