668356920 has 768 divisors, whose sum is σ = 3019161600. Its totient is φ = 128770560.

The previous prime is 668356889. The next prime is 668356943. The reversal of 668356920 is 29653866.

It is a happy number.

668356920 is a `hidden beast` number, since 6 + 6 + 83 + 569 + 2 + 0 = 666.

668356920 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 14220337 + ... + 14220383.

It is an arithmetic number, because the mean of its divisors is an integer number (3931200).

Almost surely, 2^668356920 is an apocalyptic number.

668356920 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 668356920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1509580800).

668356920 is an abundant number, since it is smaller than the sum of its proper divisors (2350804680).

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

668356920 is a wasteful number, since it uses less digits than its factorization.

668356920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110 (or 94 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 45.

The square root of 668356920 is about 25852.5998692588. The cubic root of 668356920 is about 874.3181278146.

The spelling of 668356920 in words is "six hundred sixty-eight million, three hundred fifty-six thousand, nine hundred twenty".