42406531 has 2 divisors, whose sum is σ = 42406532. Its totient is φ = 42406530.

The previous prime is 42406513. The next prime is 42406541. The reversal of 42406531 is 13560424.

Together with previous prime (42406513) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 42406531 - 2⁹ = 42406019 is a prime.

It is a super-2 number, since 2×42406531² = 3596627742907922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 42406496 and 42406505.

It is not a weakly prime, because it can be changed into another prime (42406501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21203265 + 21203266.

It is an arithmetic number, because the mean of its divisors is an integer number (21203266).

Almost surely, 2^42406531 is an apocalyptic number.

42406531 is a deficient number, since it is larger than the sum of its proper divisors (1).

42406531 is an equidigital number, since it uses as much as digits as its factorization.

42406531 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 42406531 is about 6512.0297143057. The cubic root of 42406531 is about 348.7205832427.

Adding to 42406531 its reverse (13560424), we get a palindrome (55966955).

The spelling of 42406531 in words is "forty-two million, four hundred six thousand, five hundred thirty-one".