31878416387 has 2 divisors, whose sum is σ = 31878416388. Its totient is φ = 31878416386.

The previous prime is 31878416363. The next prime is 31878416399. The reversal of 31878416387 is 78361487813.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31878416387 - 2¹⁰ = 31878415363 is a prime.

It is not a weakly prime, because it can be changed into another prime (31878416357) 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 as a sum of consecutive naturals, namely, 15939208193 + 15939208194.

It is an arithmetic number, because the mean of its divisors is an integer number (15939208194).

Almost surely, 2^31878416387 is an apocalyptic number.

31878416387 is a deficient number, since it is larger than the sum of its proper divisors (1).

31878416387 is an equidigital number, since it uses as much as digits as its factorization.

31878416387 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5419008, while the sum is 56.

The spelling of 31878416387 in words is "thirty-one billion, eight hundred seventy-eight million, four hundred sixteen thousand, three hundred eighty-seven".