1668668517 has 12 divisors (see below), whose sum is σ = 2412194304. Its totient is φ = 1111570920.

The previous prime is 1668668501. The next prime is 1668668537. The reversal of 1668668517 is 7158668661.

1668668517 is a `hidden beast` number, since 1 + 6 + 68 + 6 + 68 + 517 = 666.

It is not a de Polignac number, because 1668668517 - 2⁴ = 1668668501 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1668668537) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 60709 + ... + 83802.

It is an arithmetic number, because the mean of its divisors is an integer number (201016192).

Almost surely, 2^1668668517 is an apocalyptic number.

It is an amenable number.

1668668517 is a deficient number, since it is larger than the sum of its proper divisors (743525787).

1668668517 is a wasteful number, since it uses less digits than its factorization.

1668668517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145800 (or 145797 counting only the distinct ones).

The product of its digits is 2903040, while the sum is 54.

The square root of 1668668517 is about 40849.3392480221. The cubic root of 1668668517 is about 1186.1056027744.

The spelling of 1668668517 in words is "one billion, six hundred sixty-eight million, six hundred sixty-eight thousand, five hundred seventeen".