90687681 has 60 divisors (see below), whose sum is σ = 160258692. Its totient is φ = 50948352.

The previous prime is 90687607. The next prime is 90687691. The reversal of 90687681 is 18678609.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 18352656 + 72335025 = 4284^2 + 8505^2 .

It is not a de Polignac number, because 90687681 - 2¹⁸ = 90425537 is a prime.

It is a super-2 number, since 2×90687681² = 16448510970315522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (90687601) 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 59 ways as a sum of consecutive naturals, for example, 289581 + ... + 289893.

Almost surely, 2^90687681 is an apocalyptic number.

It is an amenable number.

90687681 is a deficient number, since it is larger than the sum of its proper divisors (69571011).

90687681 is a wasteful number, since it uses less digits than its factorization.

90687681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 412 (or 396 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 90687681 is about 9523.0079806750. The cubic root of 90687681 is about 449.2789786798.

The spelling of 90687681 in words is "ninety million, six hundred eighty-seven thousand, six hundred eighty-one".