90643865 has 16 divisors (see below), whose sum is σ = 119065296. Its totient is φ = 65836800.

The previous prime is 90643859. The next prime is 90643867. The reversal of 90643865 is 56834609.

It can be written as a sum of positive squares in 8 ways, for example, as 7997584 + 82646281 = 2828^2 + 9091^2 .

It is a de Polignac number, because none of the positive numbers 2^k-90643865 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90643867) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7466 + ... + 15395.

It is an arithmetic number, because the mean of its divisors is an integer number (7441581).

Almost surely, 2^90643865 is an apocalyptic number.

It is an amenable number.

90643865 is a deficient number, since it is larger than the sum of its proper divisors (28421431).

90643865 is a wasteful number, since it uses less digits than its factorization.

90643865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22940.

The product of its (nonzero) digits is 155520, while the sum is 41.

The square root of 90643865 is about 9520.7071691130. The cubic root of 90643865 is about 449.2066102363.

The spelling of 90643865 in words is "ninety million, six hundred forty-three thousand, eight hundred sixty-five".