4181521 has 2 divisors, whose sum is σ = 4181522. Its totient is φ = 4181520.

The previous prime is 4181509. The next prime is 4181531. The reversal of 4181521 is 1251814.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3920400 + 261121 = 1980^2 + 511^2 .

It is a cyclic number.

It is not a de Polignac number, because 4181521 - 2⁷ = 4181393 is a prime.

It is an Ulam number.

4181521 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 4181492 and 4181501.

It is not a weakly prime, because it can be changed into another prime (4181531) 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, 2090760 + 2090761.

It is an arithmetic number, because the mean of its divisors is an integer number (2090761).

Almost surely, 2^4181521 is an apocalyptic number.

It is an amenable number.

4181521 is a deficient number, since it is larger than the sum of its proper divisors (1).

4181521 is an equidigital number, since it uses as much as digits as its factorization.

4181521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 320, while the sum is 22.

The square root of 4181521 is about 2044.8767689032. The cubic root of 4181521 is about 161.1058933264.

The spelling of 4181521 in words is "four million, one hundred eighty-one thousand, five hundred twenty-one".