90990257 has 4 divisors (see below), whose sum is σ = 91825140. Its totient is φ = 90155376.

The previous prime is 90990247. The next prime is 90990311. The reversal of 90990257 is 75209909.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 48427681 + 42562576 = 6959^2 + 6524^2 .

It is a cyclic number.

It is not a de Polignac number, because 90990257 - 2²² = 86795953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90990227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 417278 + ... + 417495.

It is an arithmetic number, because the mean of its divisors is an integer number (22956285).

Almost surely, 2^90990257 is an apocalyptic number.

It is an amenable number.

90990257 is a deficient number, since it is larger than the sum of its proper divisors (834883).

90990257 is a wasteful number, since it uses less digits than its factorization.

90990257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 834882.

The product of its (nonzero) digits is 51030, while the sum is 41.

The square root of 90990257 is about 9538.8813285416. The cubic root of 90990257 is about 449.7780914112.

The spelling of 90990257 in words is "ninety million, nine hundred ninety thousand, two hundred fifty-seven".