66621667752 has 128 divisors (see below), whose sum is σ = 192514320000. Its totient is φ = 21321312768.

The previous prime is 66621667751. The next prime is 66621667757. The reversal of 66621667752 is 25776612666.

It is a super-2 number, since 2×66621667752² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (66621667751) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1091548 + ... + 1150964.

It is an arithmetic number, because the mean of its divisors is an integer number (1504018125).

Almost surely, 2^66621667752 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66621667752, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96257160000).

66621667752 is an abundant number, since it is smaller than the sum of its proper divisors (125892652248).

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

66621667752 is a wasteful number, since it uses less digits than its factorization.

66621667752 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59640 (or 59630 counting only the distinct ones).

The product of its digits is 7620480, while the sum is 54.

The spelling of 66621667752 in words is "sixty-six billion, six hundred twenty-one million, six hundred sixty-seven thousand, seven hundred fifty-two".