90681731 has 4 divisors (see below), whose sum is σ = 103636272. Its totient is φ = 77727192.

The previous prime is 90681719. The next prime is 90681743. The reversal of 90681731 is 13718609.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13718609 = 17 ⋅806977.

It is an interprime number because it is at equal distance from previous prime (90681719) and next prime (90681743).

It is a cyclic number.

It is not a de Polignac number, because 90681731 - 2¹⁴ = 90665347 is a prime.

It is a super-2 number, since 2×90681731² = 16446352674312722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 90681691 and 90681700.

It is not an unprimeable number, because it can be changed into a prime (90681431) 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, 6477260 + ... + 6477273.

It is an arithmetic number, because the mean of its divisors is an integer number (25909068).

Almost surely, 2^90681731 is an apocalyptic number.

90681731 is a deficient number, since it is larger than the sum of its proper divisors (12954541).

90681731 is a wasteful number, since it uses less digits than its factorization.

90681731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12954540.

The product of its (nonzero) digits is 9072, while the sum is 35.

The square root of 90681731 is about 9522.6955742584. The cubic root of 90681731 is about 449.2691527646.

The spelling of 90681731 in words is "ninety million, six hundred eighty-one thousand, seven hundred thirty-one".