31878768013 has 8 divisors (see below), whose sum is σ = 32008799160. Its totient is φ = 31748855040.

The previous prime is 31878767989. The next prime is 31878768041. The reversal of 31878768013 is 31086787813.

It can be written as a sum of positive squares in 4 ways, for example, as 1294704324 + 30584063689 = 35982^2 + 174883^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31878768013 - 2¹⁷ = 31878636941 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 (31878768073) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 532753 + ... + 589561.

It is an arithmetic number, because the mean of its divisors is an integer number (4001099895).

Almost surely, 2^31878768013 is an apocalyptic number.

It is an amenable number.

31878768013 is a deficient number, since it is larger than the sum of its proper divisors (130031147).

31878768013 is a wasteful number, since it uses less digits than its factorization.

31878768013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59087.

The product of its (nonzero) digits is 1354752, while the sum is 52.

The spelling of 31878768013 in words is "thirty-one billion, eight hundred seventy-eight million, seven hundred sixty-eight thousand, thirteen".