66116983766400 has 1152 divisors, whose sum is σ = 293200028372160. Its totient is φ = 13839040512000.

The previous prime is 66116983766381. The next prime is 66116983766423. The reversal of 66116983766400 is 466738961166.

66116983766400 is a `hidden beast` number, since 6 + 6 + 1 + 169 + 8 + 3 + 7 + 66 + 400 = 666.

It is a tau number, because it is divible by the number of its divisors (1152).

It is a super-2 number, since 2×66116983766400² (a number of 28 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 126545700 + ... + 127067100.

Almost surely, 2^{66116983766400} is an apocalyptic number.

66116983766400 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66116983766400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (146600014186080).

66116983766400 is an abundant number, since it is smaller than the sum of its proper divisors (227083044605760).

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

66116983766400 is a wasteful number, since it uses less digits than its factorization.

66116983766400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521492 (or 521472 counting only the distinct ones).

The product of its (nonzero) digits is 47029248, while the sum is 63.

The spelling of 66116983766400 in words is "sixty-six trillion, one hundred sixteen billion, nine hundred eighty-three million, seven hundred sixty-six thousand, four hundred".