42521431 has 4 divisors (see below), whose sum is σ = 42609232. Its totient is φ = 42433632.

The previous prime is 42521419. The next prime is 42521443. The reversal of 42521431 is 13412524.

42521431 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 an interprime number because it is at equal distance from previous prime (42521419) and next prime (42521443).

It is a cyclic number.

It is not a de Polignac number, because 42521431 - 2¹⁹ = 41997143 is a prime.

It is a super-2 number, since 2×42521431² = 3616144188575522, 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 (42521461) 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, 43170 + ... + 44143.

It is an arithmetic number, because the mean of its divisors is an integer number (10652308).

Almost surely, 2^42521431 is an apocalyptic number.

42521431 is a deficient number, since it is larger than the sum of its proper divisors (87801).

42521431 is an equidigital number, since it uses as much as digits as its factorization.

42521431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87800.

The product of its digits is 960, while the sum is 22.

The square root of 42521431 is about 6520.8458807121. The cubic root of 42521431 is about 349.0352506656.

Adding to 42521431 its reverse (13412524), we get a palindrome (55933955).

The spelling of 42521431 in words is "forty-two million, five hundred twenty-one thousand, four hundred thirty-one".