90931376581 has 2 divisors, whose sum is σ = 90931376582. Its totient is φ = 90931376580.

The previous prime is 90931376579. The next prime is 90931376623. The reversal of 90931376581 is 18567313909.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 86383088100 + 4548288481 = 293910^2 + 67441^2 .

It is a cyclic number.

It is not a de Polignac number, because 90931376581 - 2¹ = 90931376579 is a prime.

It is a super-2 number, since 2×90931376581² (a number of 23 digits) contains 22 as substring.

Together with 90931376579, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90931376521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45465688290 + 45465688291.

It is an arithmetic number, because the mean of its divisors is an integer number (45465688291).

Almost surely, 2^90931376581 is an apocalyptic number.

It is an amenable number.

90931376581 is a deficient number, since it is larger than the sum of its proper divisors (1).

90931376581 is an equidigital number, since it uses as much as digits as its factorization.

90931376581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1224720, while the sum is 52.

The spelling of 90931376581 in words is "ninety billion, nine hundred thirty-one million, three hundred seventy-six thousand, five hundred eighty-one".