664888860 has 72 divisors (see below), whose sum is σ = 2027385360. Its totient is φ = 176375808.

The previous prime is 664888823. The next prime is 664888871. The reversal of 664888860 is 68888466.

It is a junction number, because it is equal to n+sod(n) for n = 664888797 and 664888806.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25171 + ... + 44309.

It is an arithmetic number, because the mean of its divisors is an integer number (28158130).

Almost surely, 2^664888860 is an apocalyptic number.

664888860 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 664888860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1013692680).

664888860 is an abundant number, since it is smaller than the sum of its proper divisors (1362496500).

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

664888860 is a wasteful number, since it uses less digits than its factorization.

664888860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19347 (or 19342 counting only the distinct ones).

The product of its (nonzero) digits is 3538944, while the sum is 54.

The square root of 664888860 is about 25785.4389142400. The cubic root of 664888860 is about 872.8032448660.

The spelling of 664888860 in words is "six hundred sixty-four million, eight hundred eighty-eight thousand, eight hundred sixty".