664158720 has 160 divisors (see below), whose sum is σ = 2248570368. Its totient is φ = 166658048.

The previous prime is 664158707. The next prime is 664158727. The reversal of 664158720 is 27851466.

It is a tau number, because it is divible by the number of its divisors (160).

It is a super-2 number, since 2×664158720² = 882213610704076800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (664158727) 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, 128017 + ... + 133103.

Almost surely, 2^664158720 is an apocalyptic number.

664158720 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 664158720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1124285184).

664158720 is an abundant number, since it is smaller than the sum of its proper divisors (1584411648).

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

664158720 is a wasteful number, since it uses less digits than its factorization.

664158720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5130 (or 5114 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 39.

The square root of 664158720 is about 25771.2770347144. The cubic root of 664158720 is about 872.4836415901.

The spelling of 664158720 in words is "six hundred sixty-four million, one hundred fifty-eight thousand, seven hundred twenty".