664551468 has 72 divisors (see below), whose sum is σ = 1938530048. Its totient is φ = 188021088.

The previous prime is 664551421. The next prime is 664551469. The reversal of 664551468 is 864155466.

It is not an unprimeable number, because it can be changed into a prime (664551469) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13155 + ... + 38757.

Almost surely, 2^664551468 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 664551468, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (969265024).

664551468 is an abundant number, since it is smaller than the sum of its proper divisors (1273978580).

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

664551468 is a wasteful number, since it uses less digits than its factorization.

664551468 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25723 (or 25718 counting only the distinct ones).

The product of its digits is 691200, while the sum is 45.

The square root of 664551468 is about 25778.8957870581. The cubic root of 664551468 is about 872.6555877792.

The spelling of 664551468 in words is "six hundred sixty-four million, five hundred fifty-one thousand, four hundred sixty-eight".