90271681 has 2 divisors, whose sum is σ = 90271682. Its totient is φ = 90271680.

The previous prime is 90271661. The next prime is 90271723. The reversal of 90271681 is 18617209.

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., 88529281 + 1742400 = 9409^2 + 1320^2 .

It is a cyclic number.

It is not a de Polignac number, because 90271681 - 2⁷ = 90271553 is a prime.

It is a super-2 number, since 2×90271681² = 16297952781131522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (90271651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45135840 + 45135841.

It is an arithmetic number, because the mean of its divisors is an integer number (45135841).

Almost surely, 2^90271681 is an apocalyptic number.

It is an amenable number.

90271681 is a deficient number, since it is larger than the sum of its proper divisors (1).

90271681 is an equidigital number, since it uses as much as digits as its factorization.

90271681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6048, while the sum is 34.

The square root of 90271681 is about 9501.1410367387. The cubic root of 90271681 is about 448.5909522412.

The spelling of 90271681 in words is "ninety million, two hundred seventy-one thousand, six hundred eighty-one".