31899009 has 4 divisors (see below), whose sum is σ = 42532016. Its totient is φ = 21266004.

The previous prime is 31898989. The next prime is 31899019. The reversal of 31899009 is 90099813.

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.

It is not a de Polignac number, because 31899009 - 2⁹ = 31898497 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (31899019) 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, 5316499 + ... + 5316504.

It is an arithmetic number, because the mean of its divisors is an integer number (10633004).

Almost surely, 2^31899009 is an apocalyptic number.

It is an amenable number.

31899009 is a deficient number, since it is larger than the sum of its proper divisors (10633007).

31899009 is a wasteful number, since it uses less digits than its factorization.

31899009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10633006.

The product of its (nonzero) digits is 17496, while the sum is 39.

The square root of 31899009 is about 5647.9207678578. The cubic root of 31899009 is about 317.1458725524.

The spelling of 31899009 in words is "thirty-one million, eight hundred ninety-nine thousand, nine".