90690681 has 4 divisors (see below), whose sum is σ = 120920912. Its totient is φ = 60460452.

The previous prime is 90690661. The next prime is 90690703. The reversal of 90690681 is 18609609.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18609609 = 3 ⋅6203203.

It is not a de Polignac number, because 90690681 - 2⁶ = 90690617 is a prime.

It is a super-2 number, since 2×90690681² = 16449599240487522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90690661) 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, 15115111 + ... + 15115116.

It is an arithmetic number, because the mean of its divisors is an integer number (30230228).

Almost surely, 2^90690681 is an apocalyptic number.

It is an amenable number.

90690681 is a deficient number, since it is larger than the sum of its proper divisors (30230231).

90690681 is a wasteful number, since it uses less digits than its factorization.

90690681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30230230.

The product of its (nonzero) digits is 23328, while the sum is 39.

The square root of 90690681 is about 9523.1654926290. The cubic root of 90690681 is about 449.2839327598.

The spelling of 90690681 in words is "ninety million, six hundred ninety thousand, six hundred eighty-one".