3981997 has 4 divisors (see below), whose sum is σ = 3986176. Its totient is φ = 3977820.

The previous prime is 3981973. The next prime is 3982031. The reversal of 3981997 is 7991893.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 3981997 - 2⁷ = 3981869 is a prime.

It is an Ulam 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 (3981917) 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, 118 + ... + 2824.

It is an arithmetic number, because the mean of its divisors is an integer number (996544).

Almost surely, 2^3981997 is an apocalyptic number.

It is an amenable number.

3981997 is a deficient number, since it is larger than the sum of its proper divisors (4179).

3981997 is a wasteful number, since it uses less digits than its factorization.

3981997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4178.

The product of its digits is 122472, while the sum is 46.

The square root of 3981997 is about 1995.4941743839. The cubic root of 3981997 is about 158.5015971736.

The spelling of 3981997 in words is "three million, nine hundred eighty-one thousand, nine hundred ninety-seven".