66619968 has 56 divisors (see below), whose sum is σ = 179283360. Its totient is φ = 21826560.

The previous prime is 66619963. The next prime is 66619979. The reversal of 66619968 is 86991666.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 66619968.

It is not an unprimeable number, because it can be changed into a prime (66619963) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8388 + ... + 14268.

Almost surely, 2^66619968 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 66619968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89641680).

66619968 is an abundant number, since it is smaller than the sum of its proper divisors (112663392).

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

66619968 is a wasteful number, since it uses less digits than its factorization.

66619968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5955 (or 5945 counting only the distinct ones).

The product of its digits is 839808, while the sum is 51.

The square root of 66619968 is about 8162.1056106865. The cubic root of 66619968 is about 405.3854340153.

The spelling of 66619968 in words is "sixty-six million, six hundred nineteen thousand, nine hundred sixty-eight".