66888720 has 160 divisors (see below), whose sum is σ = 233020800. Its totient is φ = 17634816.

The previous prime is 66888709. The next prime is 66888781. The reversal of 66888720 is 2788866.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 373591 + ... + 373769.

It is an arithmetic number, because the mean of its divisors is an integer number (1456380).

Almost surely, 2^66888720 is an apocalyptic number.

66888720 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 66888720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116510400).

66888720 is an abundant number, since it is smaller than the sum of its proper divisors (166132080).

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

66888720 is a wasteful number, since it uses less digits than its factorization.

66888720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 374 (or 362 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 45.

The square root of 66888720 is about 8178.5524391545. The cubic root of 66888720 is about 405.9298252047.

The spelling of 66888720 in words is "sixty-six million, eight hundred eighty-eight thousand, seven hundred twenty".