1971859986 has 48 divisors (see below), whose sum is σ = 4417646688. Its totient is φ = 635236800.

The previous prime is 1971859979. The next prime is 1971860003. The reversal of 1971859986 is 6899581791.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 66481 + ... + 91451.

It is an arithmetic number, because the mean of its divisors is an integer number (92034306).

Almost surely, 2^1971859986 is an apocalyptic number.

1971859986 is an abundant number, since it is smaller than the sum of its proper divisors (2445786702).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1971859986 is a wasteful number, since it uses less digits than its factorization.

1971859986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25127 (or 25124 counting only the distinct ones).

The product of its digits is 9797760, while the sum is 63.

The square root of 1971859986 is about 44405.6301160112. The cubic root of 1971859986 is about 1253.9840851746.

The spelling of 1971859986 in words is "one billion, nine hundred seventy-one million, eight hundred fifty-nine thousand, nine hundred eighty-six".