66894912720 has 400 divisors, whose sum is σ = 248736312000. Its totient is φ = 16611526656.

The previous prime is 66894912719. The next prime is 66894912727. The reversal of 66894912720 is 2721949866.

66894912720 is a `hidden beast` number, since 6 + 6 + 89 + 491 + 2 + 72 + 0 = 666.

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66894912727) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 7259476 + ... + 7268684.

It is an arithmetic number, because the mean of its divisors is an integer number (621840780).

Almost surely, 2^66894912720 is an apocalyptic number.

66894912720 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 66894912720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124368156000).

66894912720 is an abundant number, since it is smaller than the sum of its proper divisors (181841399280).

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

66894912720 is a wasteful number, since it uses less digits than its factorization.

66894912720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9312 (or 9297 counting only the distinct ones).

The product of its (nonzero) digits is 2612736, while the sum is 54.

The spelling of 66894912720 in words is "sixty-six billion, eight hundred ninety-four million, nine hundred twelve thousand, seven hundred twenty".