664886880 has 432 divisors, whose sum is σ = 2744960400. Its totient is φ = 151538688.

The previous prime is 664886879. The next prime is 664886897. The reversal of 664886880 is 88688466.

It is a tau number, because it is divible by the number of its divisors (432).

It is a super-2 number, since 2×664886880² = 884149126392268800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1904946 + ... + 1905294.

It is an arithmetic number, because the mean of its divisors is an integer number (6354075).

Almost surely, 2^664886880 is an apocalyptic number.

664886880 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 664886880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1372480200).

664886880 is an abundant number, since it is smaller than the sum of its proper divisors (2080073520).

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

664886880 is a wasteful number, since it uses less digits than its factorization.

664886880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393 (or 366 counting only the distinct ones).

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

The square root of 664886880 is about 25785.4005204496. The cubic root of 664886880 is about 872.8023784795.

It can be divided in two parts, 6648 and 86880, that added together give a triangular number (93528 = T₄₃₂).

The spelling of 664886880 in words is "six hundred sixty-four million, eight hundred eighty-six thousand, eight hundred eighty".