66164640 has 96 divisors (see below), whose sum is σ = 209563200. Its totient is φ = 17547264.

The previous prime is 66164591. The next prime is 66164641. The reversal of 66164640 is 4646166.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66164641) 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, 147136 + ... + 147584.

It is an arithmetic number, because the mean of its divisors is an integer number (2182950).

Almost surely, 2^66164640 is an apocalyptic number.

66164640 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 66164640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104781600).

66164640 is an abundant number, since it is smaller than the sum of its proper divisors (143398560).

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

66164640 is a wasteful number, since it uses less digits than its factorization.

66164640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 774 (or 766 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 33.

The square root of 66164640 is about 8134.1649848033. The cubic root of 66164640 is about 404.4597582612.

The spelling of 66164640 in words is "sixty-six million, one hundred sixty-four thousand, six hundred forty".