66166776400 has 60 divisors (see below), whose sum is σ = 159087288124. Its totient is φ = 26446464000.

The previous prime is 66166776397. The next prime is 66166776419. The reversal of 66166776400 is 467766166.

It can be written as a sum of positive squares in 6 ways, for example, as 2062613056 + 64104163344 = 45416^2 + 253188^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 465790 + ... + 591010.

Almost surely, 2^66166776400 is an apocalyptic number.

It is an amenable number.

66166776400 is an abundant number, since it is smaller than the sum of its proper divisors (92920511724).

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

66166776400 is a wasteful number, since it uses less digits than its factorization.

66166776400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126560 (or 126549 counting only the distinct ones).

The product of its (nonzero) digits is 1524096, while the sum is 49.

The spelling of 66166776400 in words is "sixty-six billion, one hundred sixty-six million, seven hundred seventy-six thousand, four hundred".