66625649280 has 1280 divisors, whose sum is σ = 278317036800. Its totient is φ = 15065284608.

The previous prime is 66625649267. The next prime is 66625649323. The reversal of 66625649280 is 8294652666.

It is a happy number.

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

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 385119274 + ... + 385119446.

It is an arithmetic number, because the mean of its divisors is an integer number (217435185).

Almost surely, 2^66625649280 is an apocalyptic number.

66625649280 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 66625649280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (139158518400).

66625649280 is an abundant number, since it is smaller than the sum of its proper divisors (211691387520).

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

66625649280 is a wasteful number, since it uses less digits than its factorization.

66625649280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 263 (or 242 counting only the distinct ones).

The product of its (nonzero) digits is 7464960, while the sum is 54.

The spelling of 66625649280 in words is "sixty-six billion, six hundred twenty-five million, six hundred forty-nine thousand, two hundred eighty".