3981973861 has 4 divisors (see below), whose sum is σ = 3987856332. Its totient is φ = 3976091392.

The previous prime is 3981973859. The next prime is 3981973871. The reversal of 3981973861 is 1683791893.

3981973861 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3055988961 + 925984900 = 55281^2 + 30430^2 .

It is a cyclic number.

It is not a de Polignac number, because 3981973861 - 2¹ = 3981973859 is a prime.

It is a super-2 number, since 2×3981973861² = 31712231659374494642, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3981973841) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2940220 + ... + 2941573.

It is an arithmetic number, because the mean of its divisors is an integer number (996964083).

Almost surely, 2^3981973861 is an apocalyptic number.

It is an amenable number.

3981973861 is a deficient number, since it is larger than the sum of its proper divisors (5882471).

3981973861 is an equidigital number, since it uses as much as digits as its factorization.

3981973861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5882470.

The product of its digits is 1959552, while the sum is 55.

The square root of 3981973861 is about 63102.8831433240. The cubic root of 3981973861 is about 1585.0129016056.

The spelling of 3981973861 in words is "three billion, nine hundred eighty-one million, nine hundred seventy-three thousand, eight hundred sixty-one".