31230809 has 4 divisors (see below), whose sum is σ = 31242240. Its totient is φ = 31219380.

The previous prime is 31230781. The next prime is 31230811. The reversal of 31230809 is 90803213.

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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 90803213 = 109 ⋅833057.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31230809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31230209) 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, 1064 + ... + 7974.

It is an arithmetic number, because the mean of its divisors is an integer number (7810560).

Almost surely, 2^31230809 is an apocalyptic number.

It is an amenable number.

31230809 is a deficient number, since it is larger than the sum of its proper divisors (11431).

31230809 is an equidigital number, since it uses as much as digits as its factorization.

31230809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11430.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 31230809 is about 5588.4531849162. The cubic root of 31230809 is about 314.9157715507.

The spelling of 31230809 in words is "thirty-one million, two hundred thirty thousand, eight hundred nine".