3851981 has 4 divisors (see below), whose sum is σ = 4402272. Its totient is φ = 3301692.

The previous prime is 3851977. The next prime is 3851989. The reversal of 3851981 is 1891583.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 3851981 - 2² = 3851977 is a prime.

It is a super-2 number, since 2×3851981² = 29675515248722, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3851989) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 275135 + ... + 275148.

It is an arithmetic number, because the mean of its divisors is an integer number (1100568).

Almost surely, 2^3851981 is an apocalyptic number.

It is an amenable number.

3851981 is a deficient number, since it is larger than the sum of its proper divisors (550291).

3851981 is an equidigital number, since it uses as much as digits as its factorization.

3851981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 550290.

The product of its digits is 8640, while the sum is 35.

The square root of 3851981 is about 1962.6464276583. The cubic root of 3851981 is about 156.7573977738.

The spelling of 3851981 in words is "three million, eight hundred fifty-one thousand, nine hundred eighty-one".