668394444 has 48 divisors (see below), whose sum is σ = 1629492480. Its totient is φ = 212836800.

The previous prime is 668394401. The next prime is 668394469. The reversal of 668394444 is 444493866.

It is a super-2 number, since 2×668394444² = 893502265540138272, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 668394393 and 668394402.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 399642 + ... + 401310.

It is an arithmetic number, because the mean of its divisors is an integer number (33947760).

Almost surely, 2^668394444 is an apocalyptic number.

It is an amenable number.

668394444 is an abundant number, since it is smaller than the sum of its proper divisors (961098036).

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

668394444 is a wasteful number, since it uses less digits than its factorization.

668394444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3150 (or 3148 counting only the distinct ones).

The product of its digits is 1990656, while the sum is 48.

The square root of 668394444 is about 25853.3255887903. The cubic root of 668394444 is about 874.3344899800.

The spelling of 668394444 in words is "six hundred sixty-eight million, three hundred ninety-four thousand, four hundred forty-four".