90690181 has 2 divisors, whose sum is σ = 90690182. Its totient is φ = 90690180.

The previous prime is 90690179. The next prime is 90690203. The reversal of 90690181 is 18109609.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 88529281 + 2160900 = 9409^2 + 1470^2 .

It is a cyclic number.

It is not a de Polignac number, because 90690181 - 2¹ = 90690179 is a prime.

It is a super-2 number, since 2×90690181² = 16449417859625522, which contains 22 as substring.

Together with 90690179, 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 (90690151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45345090 + 45345091.

It is an arithmetic number, because the mean of its divisors is an integer number (45345091).

Almost surely, 2^90690181 is an apocalyptic number.

It is an amenable number.

90690181 is a deficient number, since it is larger than the sum of its proper divisors (1).

90690181 is an equidigital number, since it uses as much as digits as its factorization.

90690181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 34.

The square root of 90690181 is about 9523.1392408176. The cubic root of 90690181 is about 449.2831070874.

The spelling of 90690181 in words is "ninety million, six hundred ninety thousand, one hundred eighty-one".