3867939981 has 12 divisors (see below), whose sum is σ = 5595285852. Its totient is φ = 2574813696.

The previous prime is 3867939979. The next prime is 3867939983. The reversal of 3867939981 is 1899397683.

3867939981 is a `hidden beast` number, since 386 + 7 + 93 + 99 + 81 = 666.

It is an interprime number because it is at equal distance from previous prime (3867939979) and next prime (3867939983).

It can be written as a sum of positive squares in 2 ways, for example, as 3439822500 + 428117481 = 58650^2 + 20691^2 .

It is not a de Polignac number, because 3867939981 - 2¹ = 3867939979 is a prime.

It is a super-2 number, since 2×3867939981² = 29921919393236560722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3867939983) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 311316 + ... + 323501.

It is an arithmetic number, because the mean of its divisors is an integer number (466273821).

Almost surely, 2^3867939981 is an apocalyptic number.

It is an amenable number.

3867939981 is a deficient number, since it is larger than the sum of its proper divisors (1727345871).

3867939981 is a wasteful number, since it uses less digits than its factorization.

3867939981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 635500 (or 635497 counting only the distinct ones).

The product of its digits is 17635968, while the sum is 63.

The square root of 3867939981 is about 62192.7646997623. The cubic root of 3867939981 is about 1569.7358449111.

The spelling of 3867939981 in words is "three billion, eight hundred sixty-seven million, nine hundred thirty-nine thousand, nine hundred eighty-one".