664917120 has 512 divisors, whose sum is σ = 2820096000. Its totient is φ = 144764928.

The previous prime is 664917101. The next prime is 664917151. The reversal of 664917120 is 21719466.

664917120 is a `hidden beast` number, since 6 + 649 + 1 + 7 + 1 + 2 + 0 = 666.

It is a super-2 number, since 2×664917120² = 884229552938188800, which contains 22 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2781961 + ... + 2782199.

It is an arithmetic number, because the mean of its divisors is an integer number (5508000).

Almost surely, 2^664917120 is an apocalyptic number.

664917120 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 664917120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1410048000).

664917120 is an abundant number, since it is smaller than the sum of its proper divisors (2155178880).

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

664917120 is a wasteful number, since it uses less digits than its factorization.

664917120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297 (or 279 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 664917120 is about 25785.9868921087. The cubic root of 664917120 is about 872.8156103763.

The spelling of 664917120 in words is "six hundred sixty-four million, nine hundred seventeen thousand, one hundred twenty".