668221422 has 64 divisors (see below), whose sum is σ = 1520640000. Its totient is φ = 193898880.

The previous prime is 668221417. The next prime is 668221441. The reversal of 668221422 is 224122866.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 241704 + ... + 244452.

It is an arithmetic number, because the mean of its divisors is an integer number (23760000).

Almost surely, 2^668221422 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 668221422, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (760320000).

668221422 is an abundant number, since it is smaller than the sum of its proper divisors (852418578).

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

668221422 is a wasteful number, since it uses less digits than its factorization.

668221422 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2921.

The product of its digits is 18432, while the sum is 33.

The square root of 668221422 is about 25849.9791489278. The cubic root of 668221422 is about 874.2590394439.

The spelling of 668221422 in words is "six hundred sixty-eight million, two hundred twenty-one thousand, four hundred twenty-two".