42231391 has 4 divisors (see below), whose sum is σ = 42261352. Its totient is φ = 42201432.

The previous prime is 42231389. The next prime is 42231403. The reversal of 42231391 is 19313224.

42231391 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 42231391 - 2¹ = 42231389 is a prime.

It is a super-3 number, since 3×42231391³ (a number of 24 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42231311) 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 in 3 ways as a sum of consecutive naturals, for example, 12756 + ... + 15721.

It is an arithmetic number, because the mean of its divisors is an integer number (10565338).

Almost surely, 2^42231391 is an apocalyptic number.

42231391 is a deficient number, since it is larger than the sum of its proper divisors (29961).

42231391 is a wasteful number, since it uses less digits than its factorization.

42231391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29960.

The product of its digits is 1296, while the sum is 25.

The square root of 42231391 is about 6498.5683808051. The cubic root of 42231391 is about 348.2398459972.

It can be divided in two parts, 422 and 31391, that added together give a palindrome (31813).

The spelling of 42231391 in words is "forty-two million, two hundred thirty-one thousand, three hundred ninety-one".