90642815 has 4 divisors (see below), whose sum is σ = 108771384. Its totient is φ = 72514248.

The previous prime is 90642763. The next prime is 90642817. The reversal of 90642815 is 51824609.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 90642815 - 2¹² = 90638719 is a prime.

It is a super-2 number, since 2×90642815² = 16432239822248450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90642817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9064277 + ... + 9064286.

It is an arithmetic number, because the mean of its divisors is an integer number (27192846).

Almost surely, 2^90642815 is an apocalyptic number.

90642815 is a deficient number, since it is larger than the sum of its proper divisors (18128569).

90642815 is a wasteful number, since it uses less digits than its factorization.

90642815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18128568.

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 90642815 is about 9520.6520259907. The cubic root of 90642815 is about 449.2048757237.

The spelling of 90642815 in words is "ninety million, six hundred forty-two thousand, eight hundred fifteen".