9855971687 has 2 divisors, whose sum is σ = 9855971688. Its totient is φ = 9855971686.

The previous prime is 9855971659. The next prime is 9855971693. The reversal of 9855971687 is 7861795589.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 9855971687 - 2¹⁴ = 9855955303 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9855971387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4927985843 + 4927985844.

It is an arithmetic number, because the mean of its divisors is an integer number (4927985844).

Almost surely, 2^9855971687 is an apocalyptic number.

9855971687 is a deficient number, since it is larger than the sum of its proper divisors (1).

9855971687 is an equidigital number, since it uses as much as digits as its factorization.

9855971687 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38102400, while the sum is 65.

The square root of 9855971687 is about 99277.2465724146. The cubic root of 9855971687 is about 2144.0413113437.

The spelling of 9855971687 in words is "nine billion, eight hundred fifty-five million, nine hundred seventy-one thousand, six hundred eighty-seven".