668044416 has 128 divisors (see below), whose sum is σ = 1925058240. Its totient is φ = 204042240.

The previous prime is 668044411. The next prime is 668044439. The reversal of 668044416 is 614440866.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (668044411) 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, 813286 + ... + 814106.

Almost surely, 2^668044416 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 668044416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (962529120).

668044416 is an abundant number, since it is smaller than the sum of its proper divisors (1257013824).

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

668044416 is a wasteful number, since it uses less digits than its factorization.

668044416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1014 (or 1002 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 39.

The square root of 668044416 is about 25846.5552056749. Note that the first 3 decimals coincide. The cubic root of 668044416 is about 874.1818381069.

The spelling of 668044416 in words is "six hundred sixty-eight million, forty-four thousand, four hundred sixteen".