3925981 has 2 divisors, whose sum is σ = 3925982. Its totient is φ = 3925980.

The previous prime is 3925973. The next prime is 3925993. The reversal of 3925981 is 1895293.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2340900 + 1585081 = 1530^2 + 1259^2 .

It is a cyclic number.

It is not a de Polignac number, because 3925981 - 2³ = 3925973 is a prime.

It is a super-2 number, since 2×3925981² = 30826653624722, which contains 22 as substring.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 3925981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3925781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1962990 + 1962991.

It is an arithmetic number, because the mean of its divisors is an integer number (1962991).

Almost surely, 2^3925981 is an apocalyptic number.

It is an amenable number.

3925981 is a deficient number, since it is larger than the sum of its proper divisors (1).

3925981 is an equidigital number, since it uses as much as digits as its factorization.

3925981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 19440, while the sum is 37.

The square root of 3925981 is about 1981.4088422130. The cubic root of 3925981 is about 157.7548540428.

It can be divided in two parts, 39259 and 81, that added together give a triangular number (39340 = T₂₈₀).

The spelling of 3925981 in words is "three million, nine hundred twenty-five thousand, nine hundred eighty-one".