668557238469120 has 3840 divisors, whose sum is σ = 3289876234444800. Its totient is φ = 128228902502400.

The previous prime is 668557238469079. The next prime is 668557238469157. The reversal of 668557238469120 is 21964832755866.

668557238469120 is a `hidden beast` number, since 6 + 6 + 8 + 5 + 5 + 7 + 2 + 38 + 469 + 120 = 666.

It is a tau number, because it is divible by the number of its divisors (3840).

It is a super-2 number, since 2×668557238469120² (a number of 30 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 30512390965 + ... + 30512412875.

It is an arithmetic number, because the mean of its divisors is an integer number (856738602720).

It is a 1-persistent number, because it is pandigital, but 2⋅668557238469120 = 1337114476938240 is not.

Almost surely, 2^{668557238469120} is an apocalyptic number.

668557238469120 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 668557238469120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1644938117222400).

668557238469120 is an abundant number, since it is smaller than the sum of its proper divisors (2621318995975680).

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

668557238469120 is a wasteful number, since it uses less digits than its factorization.

668557238469120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21994 (or 21952 counting only the distinct ones).

The product of its (nonzero) digits is 1045094400, while the sum is 72.

The spelling of 668557238469120 in words is "six hundred sixty-eight trillion, five hundred fifty-seven billion, two hundred thirty-eight million, four hundred sixty-nine thousand, one hundred twenty".