1986271871 has 6 divisors (see below), whose sum is σ = 1998559080. Its totient is φ = 1974059748.

The previous prime is 1986271843. The next prime is 1986271877. The reversal of 1986271871 is 1781726891.

It is a de Polignac number, because none of the positive numbers 2^k-1986271871 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 (1986271877) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10811 + ... + 63948.

It is an arithmetic number, because the mean of its divisors is an integer number (333093180).

Almost surely, 2^1986271871 is an apocalyptic number.

1986271871 is a deficient number, since it is larger than the sum of its proper divisors (12287209).

1986271871 is an frugal number, since it uses more digits than its factorization.

1986271871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75085 (or 74922 counting only the distinct ones).

The product of its digits is 338688, while the sum is 50.

The square root of 1986271871 is about 44567.6101109315. The cubic root of 1986271871 is about 1257.0317024366.

The spelling of 1986271871 in words is "one billion, nine hundred eighty-six million, two hundred seventy-one thousand, eight hundred seventy-one".