668735920742400 has 2016 divisors, whose sum is σ = 2823636843675648. Its totient is φ = 148107991449600.

The previous prime is 668735920742369. The next prime is 668735920742411. The reversal of 668735920742400 is 4247029537866.

668735920742400 is a `hidden beast` number, since 6 + 6 + 8 + 73 + 5 + 92 + 0 + 74 + 2 + 400 = 666.

It is a tau number, because it is divible by the number of its divisors (2016).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 70460001655 + ... + 70460011145.

It is an arithmetic number, because the mean of its divisors is an integer number (1400613513728).

Almost surely, 2^{668735920742400} is an apocalyptic number.

668735920742400 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 668735920742400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1411818421837824).

668735920742400 is an abundant number, since it is smaller than the sum of its proper divisors (2154900922933248).

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

668735920742400 is a wasteful number, since it uses less digits than its factorization.

668735920742400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9710 (or 9678 counting only the distinct ones).

The product of its (nonzero) digits is 121927680, while the sum is 63.

The spelling of 668735920742400 in words is "six hundred sixty-eight trillion, seven hundred thirty-five billion, nine hundred twenty million, seven hundred forty-two thousand, four hundred".