31809089 has 4 divisors (see below), whose sum is σ = 34255956. Its totient is φ = 29362224.

The previous prime is 31809079. The next prime is 31809101. The reversal of 31809089 is 98090813.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 98090813 = 1297 ⋅75629.

It can be written as a sum of positive squares in 2 ways, for example, as 5880625 + 25928464 = 2425^2 + 5092^2 .

It is a cyclic number.

It is not a de Polignac number, because 31809089 - 2⁴ = 31809073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31809049) 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, 1223414 + ... + 1223439.

It is an arithmetic number, because the mean of its divisors is an integer number (8563989).

Almost surely, 2^31809089 is an apocalyptic number.

It is an amenable number.

31809089 is a deficient number, since it is larger than the sum of its proper divisors (2446867).

31809089 is a wasteful number, since it uses less digits than its factorization.

31809089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2446866.

The product of its (nonzero) digits is 15552, while the sum is 38.

The square root of 31809089 is about 5639.9546983996. The cubic root of 31809089 is about 316.8475916549.

The spelling of 31809089 in words is "thirty-one million, eight hundred nine thousand, eighty-nine".