664860240 has 240 divisors, whose sum is σ = 2458699776. Its totient is φ = 159667200.

The previous prime is 664860221. The next prime is 664860253. The reversal of 664860240 is 42068466.

It is a happy number.

664860240 is a `hidden beast` number, since 6 + 6 + 4 + 8 + 602 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

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

It is a junction number, because it is equal to n+sod(n) for n = 664860195 and 664860204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1005510 + ... + 1006170.

Almost surely, 2^664860240 is an apocalyptic number.

664860240 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 664860240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1229349888).

664860240 is an abundant number, since it is smaller than the sum of its proper divisors (1793839536).

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

664860240 is a wasteful number, since it uses less digits than its factorization.

664860240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 818 (or 809 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

The square root of 664860240 is about 25784.8839438924. The cubic root of 664860240 is about 872.7907214761.

The spelling of 664860240 in words is "six hundred sixty-four million, eight hundred sixty thousand, two hundred forty".