666794730624 has 128 divisors (see below), whose sum is σ = 1932695657280. Its totient is φ = 202006056960.

The previous prime is 666794730601. The next prime is 666794730629. The reversal of 666794730624 is 426037497666.

It is a happy number.

It is a Cunningham number, because it is equal to 816575²-1.

It is a tau number, because it is divible by the number of its divisors (128).

It is not an unprimeable number, because it can be changed into a prime (666794730629) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17946114 + ... + 17983230.

Almost surely, 2^666794730624 is an apocalyptic number.

666794730624 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 666794730624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (966347828640).

666794730624 is an abundant number, since it is smaller than the sum of its proper divisors (1265900926656).

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

666794730624 is a wasteful number, since it uses less digits than its factorization.

666794730624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41398 (or 41386 counting only the distinct ones).

The product of its (nonzero) digits is 54867456, while the sum is 60.

The spelling of 666794730624 in words is "six hundred sixty-six billion, seven hundred ninety-four million, seven hundred thirty thousand, six hundred twenty-four".