42806531 has 2 divisors, whose sum is σ = 42806532. Its totient is φ = 42806530.

The previous prime is 42806509. The next prime is 42806549. The reversal of 42806531 is 13560824.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42806531 is a prime.

It is a super-2 number, since 2×42806531² = 3664798192507922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 42806494 and 42806503.

It is not a weakly prime, because it can be changed into another prime (42806591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21403265 + 21403266.

It is an arithmetic number, because the mean of its divisors is an integer number (21403266).

Almost surely, 2^42806531 is an apocalyptic number.

42806531 is a deficient number, since it is larger than the sum of its proper divisors (1).

42806531 is an equidigital number, since it uses as much as digits as its factorization.

42806531 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 42806531 is about 6542.6700207178. The cubic root of 42806531 is about 349.8135905321.

The spelling of 42806531 in words is "forty-two million, eight hundred six thousand, five hundred thirty-one".