90997381 has 2 divisors, whose sum is σ = 90997382. Its totient is φ = 90997380.

The previous prime is 90997301. The next prime is 90997391. The reversal of 90997381 is 18379909.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 84916225 + 6081156 = 9215^2 + 2466^2 .

It is a cyclic number.

It is not a de Polignac number, because 90997381 - 2⁷ = 90997253 is a prime.

It is a super-2 number, since 2×90997381² = 16561046697718322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90997301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45498690 + 45498691.

It is an arithmetic number, because the mean of its divisors is an integer number (45498691).

Almost surely, 2^90997381 is an apocalyptic number.

It is an amenable number.

90997381 is a deficient number, since it is larger than the sum of its proper divisors (1).

90997381 is an equidigital number, since it uses as much as digits as its factorization.

90997381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 122472, while the sum is 46.

The square root of 90997381 is about 9539.2547402824. The cubic root of 90997381 is about 449.7898294280.

It can be divided in two parts, 90997 and 381, that added together give a triangular number (91378 = T₄₂₇).

The spelling of 90997381 in words is "ninety million, nine hundred ninety-seven thousand, three hundred eighty-one".