90685906 has 4 divisors (see below), whose sum is σ = 136028862. Its totient is φ = 45342952.

The previous prime is 90685897. The next prime is 90685937. The reversal of 90685906 is 60958609.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 60958609 = 29 ⋅2102021.

It can be written as a sum of positive squares in only one way, i.e., 89019225 + 1666681 = 9435^2 + 1291^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 22671475 + ... + 22671478.

Almost surely, 2^90685906 is an apocalyptic number.

90685906 is a deficient number, since it is larger than the sum of its proper divisors (45342956).

90685906 is a wasteful number, since it uses less digits than its factorization.

90685906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45342955.

The product of its (nonzero) digits is 116640, while the sum is 43.

The square root of 90685906 is about 9522.9147848755. The cubic root of 90685906 is about 449.2760474644.

The spelling of 90685906 in words is "ninety million, six hundred eighty-five thousand, nine hundred six".