90219665 has 4 divisors (see below), whose sum is σ = 108263604. Its totient is φ = 72175728.

The previous prime is 90219617. The next prime is 90219737. The reversal of 90219665 is 56691209.

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

It can be written as a sum of positive squares in 2 ways, for example, as 22963264 + 67256401 = 4792^2 + 8201^2 .

It is a cyclic number.

It is not a de Polignac number, because 90219665 - 2⁶ = 90219601 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9021962 + ... + 9021971.

It is an arithmetic number, because the mean of its divisors is an integer number (27065901).

Almost surely, 2^90219665 is an apocalyptic number.

It is an amenable number.

90219665 is a deficient number, since it is larger than the sum of its proper divisors (18043939).

90219665 is a wasteful number, since it uses less digits than its factorization.

90219665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18043938.

The product of its (nonzero) digits is 29160, while the sum is 38.

The square root of 90219665 is about 9498.4032868688. The cubic root of 90219665 is about 448.5047739036.

The spelling of 90219665 in words is "ninety million, two hundred nineteen thousand, six hundred sixty-five".