3951989 has 2 divisors, whose sum is σ = 3951990. Its totient is φ = 3951988.

The previous prime is 3951977. The next prime is 3952009. The reversal of 3951989 is 9891593.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3771364 + 180625 = 1942^2 + 425^2 .

It is an emirp because it is prime and its reverse (9891593) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3951989 - 2¹⁶ = 3886453 is a prime.

It is a super-2 number, since 2×3951989² = 31236434112242, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3851989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1975994 + 1975995.

It is an arithmetic number, because the mean of its divisors is an integer number (1975995).

Almost surely, 2^3951989 is an apocalyptic number.

It is an amenable number.

3951989 is a deficient number, since it is larger than the sum of its proper divisors (1).

3951989 is an equidigital number, since it uses as much as digits as its factorization.

3951989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 87480, while the sum is 44.

The square root of 3951989 is about 1987.9610157143. The cubic root of 3951989 is about 158.1024411777.

The spelling of 3951989 in words is "three million, nine hundred fifty-one thousand, nine hundred eighty-nine".