31961409 has 4 divisors (see below), whose sum is σ = 42615216. Its totient is φ = 21307604.

The previous prime is 31961399. The next prime is 31961429. The reversal of 31961409 is 90416913.

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 a cyclic number.

It is not a de Polignac number, because 31961409 - 2⁹ = 31960897 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31961409.

It is not an unprimeable number, because it can be changed into a prime (31961429) 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, 5326899 + ... + 5326904.

It is an arithmetic number, because the mean of its divisors is an integer number (10653804).

Almost surely, 2^31961409 is an apocalyptic number.

It is an amenable number.

31961409 is a deficient number, since it is larger than the sum of its proper divisors (10653807).

31961409 is a wasteful number, since it uses less digits than its factorization.

31961409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10653806.

The product of its (nonzero) digits is 5832, while the sum is 33.

The square root of 31961409 is about 5653.4422257595. The cubic root of 31961409 is about 317.3525353183.

The spelling of 31961409 in words is "thirty-one million, nine hundred sixty-one thousand, four hundred nine".