90491831 has 2 divisors, whose sum is σ = 90491832. Its totient is φ = 90491830.

The previous prime is 90491809. The next prime is 90491837. The reversal of 90491831 is 13819409.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 90491831 - 2⁶ = 90491767 is a prime.

It is a super-2 number, since 2×90491831² = 16377542955465122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 90491791 and 90491800.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90491837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45245915 + 45245916.

It is an arithmetic number, because the mean of its divisors is an integer number (45245916).

Almost surely, 2^90491831 is an apocalyptic number.

90491831 is a deficient number, since it is larger than the sum of its proper divisors (1).

90491831 is an equidigital number, since it uses as much as digits as its factorization.

90491831 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 90491831 is about 9512.7194324231. The cubic root of 90491831 is about 448.9553231572.

The spelling of 90491831 in words is "ninety million, four hundred ninety-one thousand, eight hundred thirty-one".