66073556736 has 864 divisors, whose sum is σ = 236143810560. Its totient is φ = 18048614400.

The previous prime is 66073556707. The next prime is 66073556737. The reversal of 66073556736 is 63765537066.

It is a happy number.

66073556736 is a `hidden beast` number, since 6 + 6 + 0 + 73 + 5 + 567 + 3 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (864).

It is a super-3 number, since 3×66073556736³ (a number of 33 digits) contains 333 as substring.

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 (66073556737) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 681170640 + ... + 681170736.

Almost surely, 2^66073556736 is an apocalyptic number.

66073556736 is a gapful number since it is divisible by the number (66) 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 66073556736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118071905280).

66073556736 is an abundant number, since it is smaller than the sum of its proper divisors (170070253824).

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

66073556736 is a wasteful number, since it uses less digits than its factorization.

66073556736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198 (or 161 counting only the distinct ones).

The product of its (nonzero) digits is 14288400, while the sum is 54.

The spelling of 66073556736 in words is "sixty-six billion, seventy-three million, five hundred fifty-six thousand, seven hundred thirty-six".