668533201920 has 528 divisors, whose sum is σ = 2421732139008. Its totient is φ = 176829972480.

The previous prime is 668533201901. The next prime is 668533201927. The reversal of 668533201920 is 29102335866.

668533201920 is a `hidden beast` number, since 6 + 6 + 8 + 533 + 20 + 1 + 92 + 0 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668533201927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 158006205 + ... + 158010435.

Almost surely, 2^668533201920 is an apocalyptic number.

668533201920 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 668533201920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1210866069504).

668533201920 is an abundant number, since it is smaller than the sum of its proper divisors (1753198937088).

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

668533201920 is a wasteful number, since it uses less digits than its factorization.

668533201920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4398 (or 4368 counting only the distinct ones).

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

The spelling of 668533201920 in words is "six hundred sixty-eight billion, five hundred thirty-three million, two hundred one thousand, nine hundred twenty".