668286446421 has 16 divisors (see below), whose sum is σ = 972262324800. Its totient is φ = 404934875520.

The previous prime is 668286446363. The next prime is 668286446441. The reversal of 668286446421 is 124644682866.

It is a happy number.

It is not a de Polignac number, because 668286446421 - 2²¹ = 668284349269 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668286446441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2024590 + ... + 2331423.

It is an arithmetic number, because the mean of its divisors is an integer number (60766395300).

Almost surely, 2^668286446421 is an apocalyptic number.

It is an amenable number.

668286446421 is a deficient number, since it is larger than the sum of its proper divisors (303975878379).

668286446421 is a wasteful number, since it uses less digits than its factorization.

668286446421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4360676.

The product of its digits is 21233664, while the sum is 57.

The spelling of 668286446421 in words is "six hundred sixty-eight billion, two hundred eighty-six million, four hundred forty-six thousand, four hundred twenty-one".