90931381 has 2 divisors, whose sum is σ = 90931382. Its totient is φ = 90931380.

The previous prime is 90931367. The next prime is 90931391. The reversal of 90931381 is 18313909.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 90897156 + 34225 = 9534^2 + 185^2 .

It is a cyclic number.

It is not a de Polignac number, because 90931381 - 2⁵ = 90931349 is a prime.

It is a super-2 number, since 2×90931381² = 16537032101134322, which contains 22 as substring.

It is equal to p_5267941 and since 90931381 and 5267941 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90931301) 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, 45465690 + 45465691.

It is an arithmetic number, because the mean of its divisors is an integer number (45465691).

Almost surely, 2^90931381 is an apocalyptic number.

It is an amenable number.

90931381 is a deficient number, since it is larger than the sum of its proper divisors (1).

90931381 is an equidigital number, since it uses as much as digits as its factorization.

90931381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5832, while the sum is 34.

The square root of 90931381 is about 9535.7947230422. The cubic root of 90931381 is about 449.6810595990.

The spelling of 90931381 in words is "ninety million, nine hundred thirty-one thousand, three hundred eighty-one".