3981951 has 6 divisors (see below), whose sum is σ = 5751720. Its totient is φ = 2654628.

The previous prime is 3981937. The next prime is 3981953. The reversal of 3981951 is 1591893.

It is a happy number.

It is not a de Polignac number, because 3981951 - 2⁷ = 3981823 is a prime.

It is an Ulam number.

3981951 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3981953) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 221211 + ... + 221228.

It is an arithmetic number, because the mean of its divisors is an integer number (958620).

Almost surely, 2^3981951 is an apocalyptic number.

3981951 is a deficient number, since it is larger than the sum of its proper divisors (1769769).

3981951 is a wasteful number, since it uses less digits than its factorization.

3981951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 442445 (or 442442 counting only the distinct ones).

The product of its digits is 9720, while the sum is 36.

The square root of 3981951 is about 1995.4826483836. The cubic root of 3981951 is about 158.5009868349.

The spelling of 3981951 in words is "three million, nine hundred eighty-one thousand, nine hundred fifty-one".