664346400 has 288 divisors, whose sum is σ = 2412970560. Its totient is φ = 157777920.

The previous prime is 664346393. The next prime is 664346401. The reversal of 664346400 is 4643466.

It is a super-2 number, since 2×664346400² = 882712278385920000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (664346401) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 774772 + ... + 775628.

It is an arithmetic number, because the mean of its divisors is an integer number (8378370).

Almost surely, 2^664346400 is an apocalyptic number.

664346400 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 664346400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1206485280).

664346400 is an abundant number, since it is smaller than the sum of its proper divisors (1748624160).

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

664346400 is a wasteful number, since it uses less digits than its factorization.

664346400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 916 (or 903 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 33.

The square root of 664346400 is about 25774.9180406068. The cubic root of 664346400 is about 872.5658168810.

Adding to 664346400 its reverse (4643466), we get a palindrome (668989866).

The spelling of 664346400 in words is "six hundred sixty-four million, three hundred forty-six thousand, four hundred".