4128391 has 2 divisors, whose sum is σ = 4128392. Its totient is φ = 4128390.

The previous prime is 4128379. The next prime is 4128401. The reversal of 4128391 is 1938214.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 4128391 - 2⁵ = 4128359 is a prime.

It is a super-2 number, since 2×4128391² = 34087224497762, which contains 22 as substring.

It is a Chen prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4128361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2064195 + 2064196.

It is an arithmetic number, because the mean of its divisors is an integer number (2064196).

Almost surely, 2^4128391 is an apocalyptic number.

4128391 is a deficient number, since it is larger than the sum of its proper divisors (1).

4128391 is an equidigital number, since it uses as much as digits as its factorization.

4128391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1728, while the sum is 28.

The square root of 4128391 is about 2031.8442361559. The cubic root of 4128391 is about 160.4206509233.

The spelling of 4128391 in words is "four million, one hundred twenty-eight thousand, three hundred ninety-one".