90921157 has 4 divisors (see below), whose sum is σ = 91397376. Its totient is φ = 90444940.

The previous prime is 90921121. The next prime is 90921167. The reversal of 90921157 is 75112909.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-90921157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90921167) 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, 237823 + ... + 238204.

It is an arithmetic number, because the mean of its divisors is an integer number (22849344).

Almost surely, 2^90921157 is an apocalyptic number.

It is an amenable number.

90921157 is a deficient number, since it is larger than the sum of its proper divisors (476219).

90921157 is a wasteful number, since it uses less digits than its factorization.

90921157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 476218.

The product of its (nonzero) digits is 5670, while the sum is 34.

The square root of 90921157 is about 9535.2586226069. The cubic root of 90921157 is about 449.6642054561.

The spelling of 90921157 in words is "ninety million, nine hundred twenty-one thousand, one hundred fifty-seven".