90815691 has 8 divisors (see below), whose sum is σ = 123140160. Its totient is φ = 59517512.

The previous prime is 90815677. The next prime is 90815701. The reversal of 90815691 is 19651809.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 90815691 - 2⁷ = 90815563 is a prime.

It is not an unprimeable number, because it can be changed into a prime (90815651) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 256365 + ... + 256718.

It is an arithmetic number, because the mean of its divisors is an integer number (15392520).

Almost surely, 2^90815691 is an apocalyptic number.

90815691 is a deficient number, since it is larger than the sum of its proper divisors (32324469).

90815691 is a wasteful number, since it uses less digits than its factorization.

90815691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 513145.

The product of its (nonzero) digits is 19440, while the sum is 39.

The square root of 90815691 is about 9529.7267012229. The cubic root of 90815691 is about 449.4902722176.

The spelling of 90815691 in words is "ninety million, eight hundred fifteen thousand, six hundred ninety-one".