668578456 has 64 divisors (see below), whose sum is σ = 1584636480. Its totient is φ = 257333760.

The previous prime is 668578453. The next prime is 668578481. The reversal of 668578456 is 654875866.

It is a junction number, because it is equal to n+sod(n) for n = 668578397 and 668578406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668578451) 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, 14526 + ... + 39346.

It is an arithmetic number, because the mean of its divisors is an integer number (24759945).

Almost surely, 2^668578456 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 668578456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (792318240).

668578456 is an abundant number, since it is smaller than the sum of its proper divisors (916058024).

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

668578456 is a wasteful number, since it uses less digits than its factorization.

668578456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24884 (or 24880 counting only the distinct ones).

The product of its digits is 9676800, while the sum is 55.

The square root of 668578456 is about 25856.8841123597. The cubic root of 668578456 is about 874.4147186920.

The spelling of 668578456 in words is "six hundred sixty-eight million, five hundred seventy-eight thousand, four hundred fifty-six".