66464320 has 84 divisors (see below), whose sum is σ = 171518580. Its totient is φ = 24520704.

The previous prime is 66464309. The next prime is 66464323. The reversal of 66464320 is 2346466.

It can be written as a sum of positive squares in 6 ways, for example, as 1048576 + 65415744 = 1024^2 + 8088^2 .

It is not an unprimeable number, because it can be changed into a prime (66464323) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 53466 + ... + 54694.

Almost surely, 2^66464320 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 66464320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85759290).

66464320 is an abundant number, since it is smaller than the sum of its proper divisors (105054260).

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

66464320 is a wasteful number, since it uses less digits than its factorization.

66464320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1272 (or 1249 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 31.

The square root of 66464320 is about 8152.5652404627. The cubic root of 66464320 is about 405.0694795191.

The spelling of 66464320 in words is "sixty-six million, four hundred sixty-four thousand, three hundred twenty".