406169221 has 2 divisors, whose sum is σ = 406169222. Its totient is φ = 406169220.

The previous prime is 406169173. The next prime is 406169233. The reversal of 406169221 is 122961604.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 317338596 + 88830625 = 17814^2 + 9425^2 .

It is a cyclic number.

It is not a de Polignac number, because 406169221 - 2¹¹ = 406167173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (406169921) 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, 203084610 + 203084611.

It is an arithmetic number, because the mean of its divisors is an integer number (203084611).

Almost surely, 2^406169221 is an apocalyptic number.

It is an amenable number.

406169221 is a deficient number, since it is larger than the sum of its proper divisors (1).

406169221 is an equidigital number, since it uses as much as digits as its factorization.

406169221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 406169221 is about 20153.6403907582. The cubic root of 406169221 is about 740.5749251361.

The spelling of 406169221 in words is "four hundred six million, one hundred sixty-nine thousand, two hundred twenty-one".