668554420 has 12 divisors (see below), whose sum is σ = 1403964324. Its totient is φ = 267421760.

The previous prime is 668554373. The next prime is 668554421. The reversal of 668554420 is 24455866.

It can be written as a sum of positive squares in 2 ways, for example, as 521756964 + 146797456 = 22842^2 + 12116^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668554421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16713841 + ... + 16713880.

It is an arithmetic number, because the mean of its divisors is an integer number (116997027).

Almost surely, 2^668554420 is an apocalyptic number.

It is an amenable number.

668554420 is an abundant number, since it is smaller than the sum of its proper divisors (735409904).

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

668554420 is a wasteful number, since it uses less digits than its factorization.

668554420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33427730 (or 33427728 counting only the distinct ones).

The product of its (nonzero) digits is 230400, while the sum is 40.

The square root of 668554420 is about 25856.4193190008. The cubic root of 668554420 is about 874.4042398998.

The spelling of 668554420 in words is "six hundred sixty-eight million, five hundred fifty-four thousand, four hundred twenty".