405021431 has 2 divisors, whose sum is σ = 405021432. Its totient is φ = 405021430.

The previous prime is 405021427. The next prime is 405021451. The reversal of 405021431 is 134120504.

It is an a-pointer prime, because the next prime (405021451) can be obtained adding 405021431 to its sum of digits (20).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 405021431 - 2² = 405021427 is a prime.

It is a super-2 number, since 2×405021431² = 328084719138575522, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (405021451) 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, 202510715 + 202510716.

It is an arithmetic number, because the mean of its divisors is an integer number (202510716).

Almost surely, 2^405021431 is an apocalyptic number.

405021431 is a deficient number, since it is larger than the sum of its proper divisors (1).

405021431 is an equidigital number, since it uses as much as digits as its factorization.

405021431 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 405021431 is about 20125.1442479302. The cubic root of 405021431 is about 739.8766722890.

Adding to 405021431 its reverse (134120504), we get a palindrome (539141935).

The spelling of 405021431 in words is "four hundred five million, twenty-one thousand, four hundred thirty-one".