66978948493056 has 144 divisors (see below), whose sum is σ = 191184327008640. Its totient is φ = 20752166522880.

The previous prime is 66978948493007. The next prime is 66978948493063. The reversal of 66978948493056 is 65039484987966.

It is a super-2 number, since 2×66978948493056² (a number of 28 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 66978948493056.

It is a congruent number.

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, 42529590 + ... + 44076341.

It is an arithmetic number, because the mean of its divisors is an integer number (1327668937560).

Almost surely, 2^{66978948493056} is an apocalyptic number.

It is an amenable number.

66978948493056 is an abundant number, since it is smaller than the sum of its proper divisors (124205378515584).

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

66978948493056 is a wasteful number, since it uses less digits than its factorization.

66978948493056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86606022 (or 86606008 counting only the distinct ones).

The product of its (nonzero) digits is 16930529280, while the sum is 84.

The spelling of 66978948493056 in words is "sixty-six trillion, nine hundred seventy-eight billion, nine hundred forty-eight million, four hundred ninety-three thousand, fifty-six".