66454770816 has 128 divisors (see below), whose sum is σ = 224153078400. Its totient is φ = 18987070464.

The previous prime is 66454770797. The next prime is 66454770859. The reversal of 66454770816 is 61807745466.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1349295 + ... + 1397678.

It is an arithmetic number, because the mean of its divisors is an integer number (1751195925).

Almost surely, 2^66454770816 is an apocalyptic number.

It is an amenable number.

66454770816 is an abundant number, since it is smaller than the sum of its proper divisors (157698307584).

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

66454770816 is a wasteful number, since it uses less digits than its factorization.

66454770816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2747003 (or 2746985 counting only the distinct ones).

The product of its (nonzero) digits is 6773760, while the sum is 54.

The spelling of 66454770816 in words is "sixty-six billion, four hundred fifty-four million, seven hundred seventy thousand, eight hundred sixteen".