3971381 has 4 divisors (see below), whose sum is σ = 3977100. Its totient is φ = 3965664.

The previous prime is 3971377. The next prime is 3971393. The reversal of 3971381 is 1831793.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1831793 = 631 ⋅2903.

It can be written as a sum of positive squares in 2 ways, for example, as 3783025 + 188356 = 1945^2 + 434^2 .

It is a cyclic number.

It is not a de Polignac number, because 3971381 - 2² = 3971377 is a prime.

It is a super-2 number, since 2×3971381² = 31543734094322, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3971311) 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, 1646 + ... + 3263.

It is an arithmetic number, because the mean of its divisors is an integer number (994275).

Almost surely, 2^3971381 is an apocalyptic number.

It is an amenable number.

3971381 is a deficient number, since it is larger than the sum of its proper divisors (5719).

3971381 is an equidigital number, since it uses as much as digits as its factorization.

3971381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5718.

The product of its digits is 4536, while the sum is 32.

The square root of 3971381 is about 1992.8324064005. The cubic root of 3971381 is about 158.3606167819.

The spelling of 3971381 in words is "three million, nine hundred seventy-one thousand, three hundred eighty-one".