3981831 has 16 divisors (see below), whose sum is σ = 6119424. Its totient is φ = 2255904.

The previous prime is 3981827. The next prime is 3981833. The reversal of 3981831 is 1381893.

It is not a de Polignac number, because 3981831 - 2² = 3981827 is a prime.

It is a super-2 number, since 2×3981831² = 31709956225122, which contains 22 as substring.

3981831 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 3981792 and 3981801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3981833) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1921 + ... + 3413.

It is an arithmetic number, because the mean of its divisors is an integer number (382464).

Almost surely, 2^3981831 is an apocalyptic number.

3981831 is a deficient number, since it is larger than the sum of its proper divisors (2137593).

3981831 is a wasteful number, since it uses less digits than its factorization.

3981831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1630.

The product of its digits is 5184, while the sum is 33.

The square root of 3981831 is about 1995.4525802434. The cubic root of 3981831 is about 158.4993946246.

The spelling of 3981831 in words is "three million, nine hundred eighty-one thousand, eight hundred thirty-one".