90187731 has 6 divisors (see below), whose sum is σ = 130271180. Its totient is φ = 60125148.

The previous prime is 90187687. The next prime is 90187817. The reversal of 90187731 is 13778109.

It is not a de Polignac number, because 90187731 - 2¹⁹ = 89663443 is a prime.

It is a super-2 number, since 2×90187731² = 16267653645856722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90187831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5010421 + ... + 5010438.

Almost surely, 2^90187731 is an apocalyptic number.

90187731 is a deficient number, since it is larger than the sum of its proper divisors (40083449).

90187731 is a wasteful number, since it uses less digits than its factorization.

90187731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10020865 (or 10020862 counting only the distinct ones).

The product of its (nonzero) digits is 10584, while the sum is 36.

The square root of 90187731 is about 9496.7221187102. The cubic root of 90187731 is about 448.4518503285.

The spelling of 90187731 in words is "ninety million, one hundred eighty-seven thousand, seven hundred thirty-one".