668134840 has 16 divisors (see below), whose sum is σ = 1503303480. Its totient is φ = 267253920.

The previous prime is 668134813. The next prime is 668134849. The reversal of 668134840 is 48431866.

It is a Harshad number since it is a multiple of its sum of digits (40), and also a Moran number because the ratio is a prime number: 16703371 = 668134840 / (6 + 6 + 8 + 1 + 3 + 4 + 8 + 4 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 668134793 and 668134802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668134849) 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, 8351646 + ... + 8351725.

Almost surely, 2^668134840 is an apocalyptic number.

It is an amenable number.

668134840 is an abundant number, since it is smaller than the sum of its proper divisors (835168640).

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

668134840 is a wasteful number, since it uses less digits than its factorization.

668134840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16703382 (or 16703378 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 40.

The square root of 668134840 is about 25848.3043931319. The cubic root of 668134840 is about 874.2212783250.

The spelling of 668134840 in words is "six hundred sixty-eight million, one hundred thirty-four thousand, eight hundred forty".