1851668687 has 12 divisors (see below), whose sum is σ = 2041216968. Its totient is φ = 1678446000.

The previous prime is 1851668669. The next prime is 1851668701. The reversal of 1851668687 is 7868661581.

It is a happy number.

It is not a de Polignac number, because 1851668687 - 2¹⁶ = 1851603151 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 (1851668627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19937 + ... + 64037.

It is an arithmetic number, because the mean of its divisors is an integer number (170101414).

Almost surely, 2^1851668687 is an apocalyptic number.

1851668687 is a deficient number, since it is larger than the sum of its proper divisors (189548281).

1851668687 is a wasteful number, since it uses less digits than its factorization.

1851668687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44470 (or 44459 counting only the distinct ones).

The product of its digits is 3870720, while the sum is 56.

The square root of 1851668687 is about 43031.0200553043. The cubic root of 1851668687 is about 1227.9700111069.

The spelling of 1851668687 in words is "one billion, eight hundred fifty-one million, six hundred sixty-eight thousand, six hundred eighty-seven".