66736668579840 has 4800 divisors, whose sum is σ = 306977180590080. Its totient is φ = 13819770961920.

The previous prime is 66736668579829. The next prime is 66736668579857. The reversal of 66736668579840 is 4897586663766.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is a self number, because there is not a number n which added to its sum of digits gives 66736668579840.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 399 ways as a sum of consecutive naturals, for example, 1419929118697 + ... + 1419929118743.

Almost surely, 2^{66736668579840} is an apocalyptic number.

66736668579840 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 66736668579840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (153488590295040).

66736668579840 is an abundant number, since it is smaller than the sum of its proper divisors (240240512010240).

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

66736668579840 is an equidigital number, since it uses as much as digits as its factorization.

66736668579840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168 (or 118 counting only the distinct ones).

The product of its (nonzero) digits is 13168189440, while the sum is 81.

The spelling of 66736668579840 in words is "sixty-six trillion, seven hundred thirty-six billion, six hundred sixty-eight million, five hundred seventy-nine thousand, eight hundred forty".