31021870939 has 4 divisors (see below), whose sum is σ = 31323054256. Its totient is φ = 30720687624.

The previous prime is 31021870927. The next prime is 31021870949. The reversal of 31021870939 is 93907812013.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93907812013 = 40387 ⋅2325199.

It is a cyclic number.

It is not a de Polignac number, because 31021870939 - 2¹⁷ = 31021739867 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31021870895 and 31021870904.

It is not an unprimeable number, because it can be changed into a prime (31021870909) 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, 150591504 + ... + 150591709.

It is an arithmetic number, because the mean of its divisors is an integer number (7830763564).

Almost surely, 2^31021870939 is an apocalyptic number.

31021870939 is a deficient number, since it is larger than the sum of its proper divisors (301183317).

31021870939 is a wasteful number, since it uses less digits than its factorization.

31021870939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 301183316.

The product of its (nonzero) digits is 81648, while the sum is 43.

The spelling of 31021870939 in words is "thirty-one billion, twenty-one million, eight hundred seventy thousand, nine hundred thirty-nine".