42431581 has 4 divisors (see below), whose sum is σ = 42506464. Its totient is φ = 42356700.

The previous prime is 42431567. The next prime is 42431651. The reversal of 42431581 is 18513424.

42431581 = T₆₃ + T₆₄ + ... + T₆₃₃.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 42431581 - 2⁵ = 42431549 is a prime.

It is a super-2 number, since 2×42431581² = 3600878132319122, which contains 22 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 (42431981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36585 + ... + 37726.

It is an arithmetic number, because the mean of its divisors is an integer number (10626616).

Almost surely, 2^42431581 is an apocalyptic number.

It is an amenable number.

42431581 is a deficient number, since it is larger than the sum of its proper divisors (74883).

42431581 is an equidigital number, since it uses as much as digits as its factorization.

42431581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74882.

The product of its digits is 3840, while the sum is 28.

The square root of 42431581 is about 6513.9527938111. The cubic root of 42431581 is about 348.7892340765.

The spelling of 42431581 in words is "forty-two million, four hundred thirty-one thousand, five hundred eighty-one".