66697945344 has 720 divisors, whose sum is σ = 222868602880. Its totient is φ = 19752284160.

The previous prime is 66697945277. The next prime is 66697945361. The reversal of 66697945344 is 44354979666.

It is a super-2 number, since 2×66697945344² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 525180609 + ... + 525180735.

Almost surely, 2^66697945344 is an apocalyptic number.

66697945344 is a gapful number since it is divisible by the number (64) 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 66697945344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111434301440).

66697945344 is an abundant number, since it is smaller than the sum of its proper divisors (156170657536).

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

66697945344 is a wasteful number, since it uses less digits than its factorization.

66697945344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 248 (or 225 counting only the distinct ones).

The product of its digits is 117573120, while the sum is 63.

The spelling of 66697945344 in words is "sixty-six billion, six hundred ninety-seven million, nine hundred forty-five thousand, three hundred forty-four".