990609409 has 4 divisors (see below), whose sum is σ = 991097280. Its totient is φ = 990121540.

The previous prime is 990609391. The next prime is 990609419. The reversal of 990609409 is 904906099.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 904906099 = 557 ⋅1624607.

It is a cyclic number.

It is not a de Polignac number, because 990609409 - 2⁹ = 990608897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (990609419) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 240877 + ... + 244954.

It is an arithmetic number, because the mean of its divisors is an integer number (247774320).

It is a Proth number, since it is equal to 30231 ⋅ 2¹⁵ + 1 and 30231 < 2¹⁵.

Almost surely, 2^990609409 is an apocalyptic number.

It is an amenable number.

990609409 is a deficient number, since it is larger than the sum of its proper divisors (487871).

990609409 is a wasteful number, since it uses less digits than its factorization.

990609409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 487870.

The product of its (nonzero) digits is 157464, while the sum is 46.

The square root of 990609409 is about 31473.9480999763. The cubic root of 990609409 is about 996.8599534277.

The spelling of 990609409 in words is "nine hundred ninety million, six hundred nine thousand, four hundred nine".