66345978 has 16 divisors (see below), whose sum is σ = 132805440. Its totient is φ = 22096416.

The previous prime is 66345959. The next prime is 66345989. The reversal of 66345978 is 87954366.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4158 + ... + 12246.

It is an arithmetic number, because the mean of its divisors is an integer number (8300340).

Almost surely, 2^66345978 is an apocalyptic number.

66345978 is an abundant number, since it is smaller than the sum of its proper divisors (66459462).

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

66345978 is a wasteful number, since it uses less digits than its factorization.

66345978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9461.

The product of its digits is 1088640, while the sum is 48.

The square root of 66345978 is about 8145.3040458905. The cubic root of 66345978 is about 404.8289233254.

The spelling of 66345978 in words is "sixty-six million, three hundred forty-five thousand, nine hundred seventy-eight".