3981811 has 4 divisors (see below), whose sum is σ = 4191400. Its totient is φ = 3772224.

The previous prime is 3981767. The next prime is 3981821. The reversal of 3981811 is 1181893.

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

It is a cyclic number.

It is not a de Polignac number, because 3981811 - 2⁷ = 3981683 is a prime.

3981811 is a lucky number.

It is a zygodrome in base 2.

It is not an unprimeable number, because it can be changed into a prime (3981821) 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, 104766 + ... + 104803.

It is an arithmetic number, because the mean of its divisors is an integer number (1047850).

Almost surely, 2^3981811 is an apocalyptic number.

3981811 is a deficient number, since it is larger than the sum of its proper divisors (209589).

3981811 is a wasteful number, since it uses less digits than its factorization.

3981811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209588.

The product of its digits is 1728, while the sum is 31.

The square root of 3981811 is about 1995.4475688426. The cubic root of 3981811 is about 158.4991292531.

It can be divided in two parts, 398 and 1811, that added together give a square (2209 = 47²).

The spelling of 3981811 in words is "three million, nine hundred eighty-one thousand, eight hundred eleven".