668361442554 has 320 divisors, whose sum is σ = 1691635663872. Its totient is φ = 195843225600.

The previous prime is 668361442547. The next prime is 668361442577. The reversal of 668361442554 is 455244163866.

668361442554 is a `hidden beast` number, since 6 + 6 + 8 + 36 + 14 + 42 + 554 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 668361442554.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 1683529884 + ... + 1683530280.

Almost surely, 2^668361442554 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 668361442554, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (845817831936).

668361442554 is an abundant number, since it is smaller than the sum of its proper divisors (1023274221318).

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

668361442554 is a wasteful number, since it uses less digits than its factorization.

668361442554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 803 (or 794 counting only the distinct ones).

The product of its digits is 16588800, while the sum is 54.

The spelling of 668361442554 in words is "six hundred sixty-eight billion, three hundred sixty-one million, four hundred forty-two thousand, five hundred fifty-four".