66144728820 has 24 divisors (see below), whose sum is σ = 185205240864. Its totient is φ = 17638594336.

The previous prime is 66144728809. The next prime is 66144728827. The reversal of 66144728820 is 2882744166.

It is a self number, because there is not a number n which added to its sum of digits gives 66144728820.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66144728827) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 551206014 + ... + 551206133.

It is an arithmetic number, because the mean of its divisors is an integer number (7716885036).

Almost surely, 2^66144728820 is an apocalyptic number.

66144728820 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66144728820 is an abundant number, since it is smaller than the sum of its proper divisors (119060512044).

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

66144728820 is a wasteful number, since it uses less digits than its factorization.

66144728820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1102412159 (or 1102412157 counting only the distinct ones).

The product of its (nonzero) digits is 1032192, while the sum is 48.

The spelling of 66144728820 in words is "sixty-six billion, one hundred forty-four million, seven hundred twenty-eight thousand, eight hundred twenty".