66633139650 has 768 divisors, whose sum is σ = 234653552640. Its totient is φ = 12076646400.

The previous prime is 66633139603. The next prime is 66633139681. The reversal of 66633139650 is 5693133666.

It is a self number, because there is not a number n which added to its sum of digits gives 66633139650.

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 197724282 + ... + 197724618.

It is an arithmetic number, because the mean of its divisors is an integer number (305538480).

Almost surely, 2^66633139650 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66633139650, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117326776320).

66633139650 is an abundant number, since it is smaller than the sum of its proper divisors (168020412990).

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

66633139650 is a wasteful number, since it uses less digits than its factorization.

66633139650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 459 (or 454 counting only the distinct ones).

The product of its (nonzero) digits is 1574640, while the sum is 48.

The spelling of 66633139650 in words is "sixty-six billion, six hundred thirty-three million, one hundred thirty-nine thousand, six hundred fifty".