31440091 has 4 divisors (see below), whose sum is σ = 31456512. Its totient is φ = 31423672.

The previous prime is 31440083. The next prime is 31440109. The reversal of 31440091 is 19004413.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 31440091 - 2³ = 31440083 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31440001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4891 + ... + 9316.

It is an arithmetic number, because the mean of its divisors is an integer number (7864128).

Almost surely, 2^31440091 is an apocalyptic number.

31440091 is a deficient number, since it is larger than the sum of its proper divisors (16421).

31440091 is a wasteful number, since it uses less digits than its factorization.

31440091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16420.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 31440091 is about 5607.1464222009. The cubic root of 31440091 is about 315.6176375893.

The spelling of 31440091 in words is "thirty-one million, four hundred forty thousand, ninety-one".