1668628687 has 4 divisors (see below), whose sum is σ = 1820322216. Its totient is φ = 1516935160.

The previous prime is 1668628667. The next prime is 1668628711. The reversal of 1668628687 is 7868268661.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1668628687 - 2¹¹ = 1668626639 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1668628607) 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, 75846748 + ... + 75846769.

It is an arithmetic number, because the mean of its divisors is an integer number (455080554).

Almost surely, 2^1668628687 is an apocalyptic number.

1668628687 is a deficient number, since it is larger than the sum of its proper divisors (151693529).

1668628687 is a wasteful number, since it uses less digits than its factorization.

1668628687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151693528.

The product of its digits is 9289728, while the sum is 58.

The square root of 1668628687 is about 40848.8517219273. The cubic root of 1668628687 is about 1186.0961655172.

The spelling of 1668628687 in words is "one billion, six hundred sixty-eight million, six hundred twenty-eight thousand, six hundred eighty-seven".