78971991356 has 12 divisors (see below), whose sum is σ = 138203707320. Its totient is φ = 39485217840.

The previous prime is 78971991347. The next prime is 78971991391. The reversal of 78971991356 is 65319917987.

It is a junction number, because it is equal to n+sod(n) for n = 78971991292 and 78971991301.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 75671 + ... + 404561.

It is an arithmetic number, because the mean of its divisors is an integer number (11516975610).

Almost surely, 2^78971991356 is an apocalyptic number.

It is an amenable number.

78971991356 is a deficient number, since it is larger than the sum of its proper divisors (59231715964).

78971991356 is a wasteful number, since it uses less digits than its factorization.

78971991356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 388924 (or 388922 counting only the distinct ones).

The product of its digits is 25719120, while the sum is 65.

The spelling of 78971991356 in words is "seventy-eight billion, nine hundred seventy-one million, nine hundred ninety-one thousand, three hundred fifty-six".