90198809 has 8 divisors (see below), whose sum is σ = 94636800. Its totient is φ = 85856400.

The previous prime is 90198769. The next prime is 90198841. The reversal of 90198809 is 90889109.

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 90198809 - 2⁸ = 90198553 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 90198809.

It is not an unprimeable number, because it can be changed into a prime (90198869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21959 + ... + 25740.

It is an arithmetic number, because the mean of its divisors is an integer number (11829600).

Almost surely, 2^90198809 is an apocalyptic number.

It is an amenable number.

90198809 is a deficient number, since it is larger than the sum of its proper divisors (4437991).

90198809 is a wasteful number, since it uses less digits than its factorization.

90198809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47791.

The product of its (nonzero) digits is 46656, while the sum is 44.

The square root of 90198809 is about 9497.3053546782. The cubic root of 90198809 is about 448.4702110898.

The spelling of 90198809 in words is "ninety million, one hundred ninety-eight thousand, eight hundred nine".