90857791 has 4 divisors (see below), whose sum is σ = 95639800. Its totient is φ = 86075784.

The previous prime is 90857773. The next prime is 90857803. The reversal of 90857791 is 19775809.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19775809 = 4447².

It is a cyclic number.

It is not a de Polignac number, because 90857791 - 2⁹ = 90857279 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 (90857761) 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, 2390976 + ... + 2391013.

It is an arithmetic number, because the mean of its divisors is an integer number (23909950).

Almost surely, 2^90857791 is an apocalyptic number.

90857791 is a deficient number, since it is larger than the sum of its proper divisors (4782009).

90857791 is a wasteful number, since it uses less digits than its factorization.

90857791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4782008.

The product of its (nonzero) digits is 158760, while the sum is 46.

The square root of 90857791 is about 9531.9353229027. The cubic root of 90857791 is about 449.5597191631.

The spelling of 90857791 in words is "ninety million, eight hundred fifty-seven thousand, seven hundred ninety-one".