405406931 has 2 divisors, whose sum is σ = 405406932. Its totient is φ = 405406930.

The previous prime is 405406927. The next prime is 405406957. The reversal of 405406931 is 139604504.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 405406931 - 2² = 405406927 is a prime.

It is a super-4 number, since 4×405406931⁴ (a number of 36 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (405406961) 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, 202703465 + 202703466.

It is an arithmetic number, because the mean of its divisors is an integer number (202703466).

Almost surely, 2^405406931 is an apocalyptic number.

405406931 is a deficient number, since it is larger than the sum of its proper divisors (1).

405406931 is an equidigital number, since it uses as much as digits as its factorization.

405406931 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 405406931 is about 20134.7195411309. The cubic root of 405406931 is about 740.1113364256. Note that the first 3 decimals are identical.

The spelling of 405406931 in words is "four hundred five million, four hundred six thousand, nine hundred thirty-one".