90899909 has 4 divisors (see below), whose sum is σ = 91425516. Its totient is φ = 90374304.

The previous prime is 90899903. The next prime is 90899917. The reversal of 90899909 is 90999809.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90999809 = 619 ⋅147011.

It can be written as a sum of positive squares in 2 ways, for example, as 86397025 + 4502884 = 9295^2 + 2122^2 .

It is a cyclic number.

It is not a de Polignac number, because 90899909 - 2²⁴ = 74122693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90899903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 262544 + ... + 262889.

It is an arithmetic number, because the mean of its divisors is an integer number (22856379).

Almost surely, 2^90899909 is an apocalyptic number.

It is an amenable number.

90899909 is a deficient number, since it is larger than the sum of its proper divisors (525607).

90899909 is a wasteful number, since it uses less digits than its factorization.

90899909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 525606.

The product of its (nonzero) digits is 472392, while the sum is 53.

The square root of 90899909 is about 9534.1443769223. The cubic root of 90899909 is about 449.6291743378.

The spelling of 90899909 in words is "ninety million, eight hundred ninety-nine thousand, nine hundred nine".