3992221 has 2 divisors, whose sum is σ = 3992222. Its totient is φ = 3992220.

The previous prime is 3992213. The next prime is 3992231. The reversal of 3992221 is 1222993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3956121 + 36100 = 1989^2 + 190^2 .

It is an emirp because it is prime and its reverse (1222993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3992221 - 2³ = 3992213 is a prime.

3992221 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 3992221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3992201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1996110 + 1996111.

It is an arithmetic number, because the mean of its divisors is an integer number (1996111).

Almost surely, 2^3992221 is an apocalyptic number.

It is an amenable number.

3992221 is a deficient number, since it is larger than the sum of its proper divisors (1).

3992221 is an equidigital number, since it uses as much as digits as its factorization.

3992221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1944, while the sum is 28.

The square root of 3992221 is about 1998.0543035663. The cubic root of 3992221 is about 158.6371351444.

The spelling of 3992221 in words is "three million, nine hundred ninety-two thousand, two hundred twenty-one".