405713221 has 2 divisors, whose sum is σ = 405713222. Its totient is φ = 405713220.

The previous prime is 405713179. The next prime is 405713281. The reversal of 405713221 is 122317504.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 210105025 + 195608196 = 14495^2 + 13986^2 .

It is a cyclic number.

It is not a de Polignac number, because 405713221 - 2⁷ = 405713093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (405713281) 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, 202856610 + 202856611.

It is an arithmetic number, because the mean of its divisors is an integer number (202856611).

Almost surely, 2^405713221 is an apocalyptic number.

It is an amenable number.

405713221 is a deficient number, since it is larger than the sum of its proper divisors (1).

405713221 is an equidigital number, since it uses as much as digits as its factorization.

405713221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 405713221 is about 20142.3241211137. The cubic root of 405713221 is about 740.2976772921.

The spelling of 405713221 in words is "four hundred five million, seven hundred thirteen thousand, two hundred twenty-one".