405356681 has 2 divisors, whose sum is σ = 405356682. Its totient is φ = 405356680.

The previous prime is 405356647. The next prime is 405356711. The reversal of 405356681 is 186653504.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 405015625 + 341056 = 20125^2 + 584^2 .

It is a cyclic number.

It is not a de Polignac number, because 405356681 - 2¹⁴ = 405340297 is a prime.

It is a super-2 number, since 2×405356681² = 328628077662671522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (405353681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202678340 + 202678341.

It is an arithmetic number, because the mean of its divisors is an integer number (202678341).

Almost surely, 2^405356681 is an apocalyptic number.

It is an amenable number.

405356681 is a deficient number, since it is larger than the sum of its proper divisors (1).

405356681 is an equidigital number, since it uses as much as digits as its factorization.

405356681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 86400, while the sum is 38.

The square root of 405356681 is about 20133.4716579133. The cubic root of 405356681 is about 740.0807563438.

The spelling of 405356681 in words is "four hundred five million, three hundred fifty-six thousand, six hundred eighty-one".