405685831 has 2 divisors, whose sum is σ = 405685832. Its totient is φ = 405685830.

The previous prime is 405685789. The next prime is 405685849. The reversal of 405685831 is 138586504.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 405685831 - 2⁷ = 405685703 is a prime.

It is a super-2 number, since 2×405685831² = 329161986948321122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (405085831) 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 as a sum of consecutive naturals, namely, 202842915 + 202842916.

It is an arithmetic number, because the mean of its divisors is an integer number (202842916).

Almost surely, 2^405685831 is an apocalyptic number.

405685831 is a deficient number, since it is larger than the sum of its proper divisors (1).

405685831 is an equidigital number, since it uses as much as digits as its factorization.

405685831 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 115200, while the sum is 40.

The square root of 405685831 is about 20141.6441980291. The cubic root of 405685831 is about 740.2810175691.

The spelling of 405685831 in words is "four hundred five million, six hundred eighty-five thousand, eight hundred thirty-one".