66403668 has 48 divisors (see below), whose sum is σ = 165150720. Its totient is φ = 20717664.

The previous prime is 66403663. The next prime is 66403669. The reversal of 66403668 is 86630466.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66403663) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10413 + ... + 15531.

It is an arithmetic number, because the mean of its divisors is an integer number (3440640).

Almost surely, 2^66403668 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 66403668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82575360).

66403668 is an abundant number, since it is smaller than the sum of its proper divisors (98747052).

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

66403668 is a wasteful number, since it uses less digits than its factorization.

66403668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5196 (or 5194 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 39.

The square root of 66403668 is about 8148.8445806752. The cubic root of 66403668 is about 404.9462266665.

The spelling of 66403668 in words is "sixty-six million, four hundred three thousand, six hundred sixty-eight".