1978716178791 has 144 divisors (see below), whose sum is σ = 3268244546112. Its totient is φ = 1151820933120.

The previous prime is 1978716178771. The next prime is 1978716178793.

1978716178791 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1978716178791 - 2¹⁷ = 1978716047719 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978716178793) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1056441231 + ... + 1056443103.

Almost surely, 2^{1978716178791} is an apocalyptic number.

1978716178791 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1978716178791 is a deficient number, since it is larger than the sum of its proper divisors (1289528367321).

1978716178791 is a wasteful number, since it uses less digits than its factorization.

1978716178791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2262 (or 2248 counting only the distinct ones).

The product of its digits is 74680704, while the sum is 72.

The spelling of 1978716178791 in words is "one trillion, nine hundred seventy-eight billion, seven hundred sixteen million, one hundred seventy-eight thousand, seven hundred ninety-one".