66215004978 has 64 divisors (see below), whose sum is σ = 141343488000. Its totient is φ = 20620189440.

The previous prime is 66215004967. The next prime is 66215004983. The reversal of 66215004978 is 87940051266.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2818123 + ... + 2841521.

It is an arithmetic number, because the mean of its divisors is an integer number (2208492000).

Almost surely, 2^66215004978 is an apocalyptic number.

66215004978 is an abundant number, since it is smaller than the sum of its proper divisors (75128483022).

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

66215004978 is a wasteful number, since it uses less digits than its factorization.

66215004978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23767.

The product of its (nonzero) digits is 725760, while the sum is 48.

The spelling of 66215004978 in words is "sixty-six billion, two hundred fifteen million, four thousand, nine hundred seventy-eight".