78644131431986 has 32 divisors (see below), whose sum is σ = 119957947758000. Its totient is φ = 38663853161472.

The previous prime is 78644131431923. The next prime is 78644131431997. The reversal of 78644131431986 is 68913413144687.

It can be written as a sum of positive squares in 8 ways, for example, as 26591874606361 + 52052256825625 = 5156731^2 + 7214725^2 .

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 88228700 + ... + 89115608.

Almost surely, 2^{78644131431986} is an apocalyptic number.

78644131431986 is a deficient number, since it is larger than the sum of its proper divisors (41313816326014).

78644131431986 is a wasteful number, since it uses less digits than its factorization.

78644131431986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 890126.

The product of its digits is 83607552, while the sum is 65.

The spelling of 78644131431986 in words is "seventy-eight trillion, six hundred forty-four billion, one hundred thirty-one million, four hundred thirty-one thousand, nine hundred eighty-six".