42090531 has 16 divisors (see below), whose sum is σ = 64802304. Its totient is φ = 23802624.

The previous prime is 42090527. The next prime is 42090557. The reversal of 42090531 is 13509024.

It is not a de Polignac number, because 42090531 - 2² = 42090527 is a prime.

It is a super-2 number, since 2×42090531² = 3543225599723922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (42090031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8295 + ... + 12368.

It is an arithmetic number, because the mean of its divisors is an integer number (4050144).

Almost surely, 2^42090531 is an apocalyptic number.

42090531 is a deficient number, since it is larger than the sum of its proper divisors (22711773).

42090531 is a wasteful number, since it uses less digits than its factorization.

42090531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20770.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 42090531 is about 6487.7215569104. The cubic root of 42090531 is about 347.8522377705.

Adding to 42090531 its reverse (13509024), we get a palindrome (55599555).

It can be divided in two parts, 420 and 90531, that added together give a triangular number (90951 = T₄₂₆).

The spelling of 42090531 in words is "forty-two million, ninety thousand, five hundred thirty-one".