4191521 has 2 divisors, whose sum is σ = 4191522. Its totient is φ = 4191520.

The previous prime is 4191491. The next prime is 4191527. The reversal of 4191521 is 1251914.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4145296 + 46225 = 2036^2 + 215^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-4191521 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (4191527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2095760 + 2095761.

It is an arithmetic number, because the mean of its divisors is an integer number (2095761).

Almost surely, 2^4191521 is an apocalyptic number.

It is an amenable number.

4191521 is a deficient number, since it is larger than the sum of its proper divisors (1).

4191521 is an equidigital number, since it uses as much as digits as its factorization.

4191521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 360, while the sum is 23.

The square root of 4191521 is about 2047.3204438973. The cubic root of 4191521 is about 161.2342179534.

The spelling of 4191521 in words is "four million, one hundred ninety-one thousand, five hundred twenty-one".