115771971978 has 32 divisors (see below), whose sum is σ = 277061131200. Its totient is φ = 35622145008.

The previous prime is 115771971923. The next prime is 115771972003. The reversal of 115771971978 is 879179177511.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 82457968 + ... + 82459371.

It is an arithmetic number, because the mean of its divisors is an integer number (8658160350).

Almost surely, 2^115771971978 is an apocalyptic number.

115771971978 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

115771971978 is an abundant number, since it is smaller than the sum of its proper divisors (161289159222).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

115771971978 is a wasteful number, since it uses less digits than its factorization.

115771971978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164917363 (or 164917357 counting only the distinct ones).

The product of its digits is 7779240, while the sum is 63.

The spelling of 115771971978 in words is "one hundred fifteen billion, seven hundred seventy-one million, nine hundred seventy-one thousand, nine hundred seventy-eight".