31121879 has 4 divisors (see below), whose sum is σ = 31349184. Its totient is φ = 30894576.

The previous prime is 31121869. The next prime is 31121887. The reversal of 31121879 is 97812113.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31121879 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31121819) 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, 113447 + ... + 113720.

It is an arithmetic number, because the mean of its divisors is an integer number (7837296).

Almost surely, 2^31121879 is an apocalyptic number.

31121879 is a deficient number, since it is larger than the sum of its proper divisors (227305).

31121879 is a wasteful number, since it uses less digits than its factorization.

31121879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 227304.

The product of its digits is 3024, while the sum is 32.

The square root of 31121879 is about 5578.6986833849. The cubic root of 31121879 is about 314.5492132675.

The spelling of 31121879 in words is "thirty-one million, one hundred twenty-one thousand, eight hundred seventy-nine".