42555391 has 2 divisors, whose sum is σ = 42555392. Its totient is φ = 42555390.

The previous prime is 42555389. The next prime is 42555413. The reversal of 42555391 is 19355524.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 42555391 - 2¹ = 42555389 is a prime.

It is a super-2 number, since 2×42555391² = 3621922606325762, which contains 22 as substring.

Together with 42555389, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42555361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21277695 + 21277696.

It is an arithmetic number, because the mean of its divisors is an integer number (21277696).

Almost surely, 2^42555391 is an apocalyptic number.

42555391 is a deficient number, since it is larger than the sum of its proper divisors (1).

42555391 is an equidigital number, since it uses as much as digits as its factorization.

42555391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27000, while the sum is 34.

The square root of 42555391 is about 6523.4493176540. The cubic root of 42555391 is about 349.1281456496.

The spelling of 42555391 in words is "forty-two million, five hundred fifty-five thousand, three hundred ninety-one".