3967581 has 4 divisors (see below), whose sum is σ = 5290112. Its totient is φ = 2645052.

The previous prime is 3967571. The next prime is 3967609. The reversal of 3967581 is 1857693.

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 not a de Polignac number, because 3967581 - 2⁶ = 3967517 is a prime.

It is a super-2 number, since 2×3967581² = 31483397983122, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3967541) 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, 661261 + ... + 661266.

It is an arithmetic number, because the mean of its divisors is an integer number (1322528).

Almost surely, 2^3967581 is an apocalyptic number.

It is an amenable number.

3967581 is a deficient number, since it is larger than the sum of its proper divisors (1322531).

3967581 is a wasteful number, since it uses less digits than its factorization.

3967581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1322530.

The product of its digits is 45360, while the sum is 39.

The square root of 3967581 is about 1991.8787613708. The cubic root of 3967581 is about 158.3100917563.

The spelling of 3967581 in words is "three million, nine hundred sixty-seven thousand, five hundred eighty-one".