90818731 has 4 divisors (see below), whose sum is σ = 93033864. Its totient is φ = 88603600.

The previous prime is 90818729. The next prime is 90818737. The reversal of 90818731 is 13781809.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13781809 = 1153 ⋅11953.

It is a cyclic number.

It is not a de Polignac number, because 90818731 - 2¹ = 90818729 is a prime.

It is a super-2 number, since 2×90818731² = 16496083800900722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90818737) 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, 1107505 + ... + 1107586.

It is an arithmetic number, because the mean of its divisors is an integer number (23258466).

Almost surely, 2^90818731 is an apocalyptic number.

90818731 is a deficient number, since it is larger than the sum of its proper divisors (2215133).

90818731 is a wasteful number, since it uses less digits than its factorization.

90818731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2215132.

The product of its (nonzero) digits is 12096, while the sum is 37.

The square root of 90818731 is about 9529.8862007896. The cubic root of 90818731 is about 449.4952876327.

The spelling of 90818731 in words is "ninety million, eight hundred eighteen thousand, seven hundred thirty-one".