42806831 has 2 divisors, whose sum is σ = 42806832. Its totient is φ = 42806830.

The previous prime is 42806789. The next prime is 42806837. The reversal of 42806831 is 13860824.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42806831 is a prime.

It is a super-2 number, since 2×42806831² = 3664849560525122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42806837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21403415 + 21403416.

It is an arithmetic number, because the mean of its divisors is an integer number (21403416).

Almost surely, 2^42806831 is an apocalyptic number.

42806831 is a deficient number, since it is larger than the sum of its proper divisors (1).

42806831 is an equidigital number, since it uses as much as digits as its factorization.

42806831 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 42806831 is about 6542.6929470975. The cubic root of 42806831 is about 349.8144077270.

It can be divided in two parts, 4280 and 6831, that added together give a palindrome (11111).

The spelling of 42806831 in words is "forty-two million, eight hundred six thousand, eight hundred thirty-one".