66451968 has 320 divisors, whose sum is σ = 235699200. Its totient is φ = 18247680.

The previous prime is 66451967. The next prime is 66451981. The reversal of 66451968 is 86915466.

Its product of digits (311040) is a multiple of the sum of its prime factors (80).

It is a zygodrome in base 4.

It is not an unprimeable number, because it can be changed into a prime (66451961) 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, 2889205 + ... + 2889227.

It is an arithmetic number, because the mean of its divisors is an integer number (736560).

Almost surely, 2^66451968 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 66451968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117849600).

66451968 is an abundant number, since it is smaller than the sum of its proper divisors (169247232).

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

66451968 is a wasteful number, since it uses less digits than its factorization.

66451968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80 (or 58 counting only the distinct ones).

The product of its digits is 311040, while the sum is 45.

The square root of 66451968 is about 8151.8076522941. The cubic root of 66451968 is about 405.0443847104.

The spelling of 66451968 in words is "sixty-six million, four hundred fifty-one thousand, nine hundred sixty-eight".