66197935978 has 12 divisors (see below), whose sum is σ = 105481487142. Its totient is φ = 31151969600.

The previous prime is 66197935957. The next prime is 66197936039. The reversal of 66197935978 is 87953979166.

It can be written as a sum of positive squares in 3 ways, for example, as 64426115329 + 1771820649 = 253823^2 + 42093^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 57264073 + ... + 57265228.

Almost surely, 2^66197935978 is an apocalyptic number.

66197935978 is a deficient number, since it is larger than the sum of its proper divisors (39283551164).

66197935978 is a wasteful number, since it uses less digits than its factorization.

66197935978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114529337 (or 114529320 counting only the distinct ones).

The product of its digits is 154314720, while the sum is 70.

The spelling of 66197935978 in words is "sixty-six billion, one hundred ninety-seven million, nine hundred thirty-five thousand, nine hundred seventy-eight".