1668393831 has 8 divisors (see below), whose sum is σ = 2395642480. Its totient is φ = 1026703872.

The previous prime is 1668393829. The next prime is 1668393833. The reversal of 1668393831 is 1383938661.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1668393829) and next prime (1668393833).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1668393831 - 2¹ = 1668393829 is a prime.

It is a super-2 number, since 2×1668393831² = 5567075950637713122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1668393833) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21389626 + ... + 21389703.

It is an arithmetic number, because the mean of its divisors is an integer number (299455310).

Almost surely, 2^1668393831 is an apocalyptic number.

1668393831 is a deficient number, since it is larger than the sum of its proper divisors (727248649).

1668393831 is a wasteful number, since it uses less digits than its factorization.

1668393831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42779345.

The product of its digits is 559872, while the sum is 48.

The square root of 1668393831 is about 40845.9769255186. The cubic root of 1668393831 is about 1186.0405160542.

The spelling of 1668393831 in words is "one billion, six hundred sixty-eight million, three hundred ninety-three thousand, eight hundred thirty-one".