3961831986 has 120 divisors (see below), whose sum is σ = 10364452956. Its totient is φ = 1127831040.

The previous prime is 3961831933. The next prime is 3961832003. The reversal of 3961831986 is 6891381693.

3961831986 is a `hidden beast` number, since 3 + 9 + 618 + 3 + 19 + 8 + 6 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 3866476761 + 95355225 = 62181^2 + 9765^2 .

It is a super-2 number, since 2×3961831986² = 31392225370585408392, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 2674366 + ... + 2675846.

Almost surely, 2^3961831986 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3961831986, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5182226478).

3961831986 is an abundant number, since it is smaller than the sum of its proper divisors (6402620970).

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

3961831986 is a wasteful number, since it uses less digits than its factorization.

3961831986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1846 (or 1830 counting only the distinct ones).

The product of its digits is 1679616, while the sum is 54.

The square root of 3961831986 is about 62943.0852913964. The cubic root of 3961831986 is about 1582.3359116493.

The spelling of 3961831986 in words is "three billion, nine hundred sixty-one million, eight hundred thirty-one thousand, nine hundred eighty-six".