668574720 has 264 divisors, whose sum is σ = 2529109440. Its totient is φ = 161955840.

The previous prime is 668574677. The next prime is 668574761. The reversal of 668574720 is 27475866.

668574720 is a `hidden beast` number, since 6 + 6 + 8 + 574 + 72 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (264).

It is a Harshad number since it is a multiple of its sum of digits (45).

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, 506221 + ... + 507539.

It is an arithmetic number, because the mean of its divisors is an integer number (9579960).

Almost surely, 2^668574720 is an apocalyptic number.

668574720 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 668574720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1264554720).

668574720 is an abundant number, since it is smaller than the sum of its proper divisors (1860534720).

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

668574720 is a wasteful number, since it uses less digits than its factorization.

668574720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1361 (or 1340 counting only the distinct ones).

The product of its (nonzero) digits is 564480, while the sum is 45.

The square root of 668574720 is about 25856.8118684419. The cubic root of 668574720 is about 874.4130899530.

The spelling of 668574720 in words is "six hundred sixty-eight million, five hundred seventy-four thousand, seven hundred twenty".