1668626694 has 72 divisors (see below), whose sum is σ = 4245165288. Its totient is φ = 472268160.

The previous prime is 1668626669. The next prime is 1668626717. The reversal of 1668626694 is 4966268661.

1668626694 is a `hidden beast` number, since 1 + 6 + 6 + 8 + 626 + 6 + 9 + 4 = 666.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1668626694.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 85534 + ... + 103214.

It is an arithmetic number, because the mean of its divisors is an integer number (58960629).

Almost surely, 2^1668626694 is an apocalyptic number.

1668626694 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1668626694, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2122582644).

1668626694 is an abundant number, since it is smaller than the sum of its proper divisors (2576538594).

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

1668626694 is a wasteful number, since it uses less digits than its factorization.

1668626694 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17810 (or 17800 counting only the distinct ones).

The product of its digits is 4478976, while the sum is 54.

The square root of 1668626694 is about 40848.8273271094. The cubic root of 1668626694 is about 1186.0956932950.

The spelling of 1668626694 in words is "one billion, six hundred sixty-eight million, six hundred twenty-six thousand, six hundred ninety-four".