405609121 has 2 divisors, whose sum is σ = 405609122. Its totient is φ = 405609120.

The previous prime is 405609101. The next prime is 405609181. The reversal of 405609121 is 121906504.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 402564096 + 3045025 = 20064^2 + 1745^2 .

It is a cyclic number.

It is not a de Polignac number, because 405609121 - 2¹¹ = 405607073 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 405609121.

It is not a weakly prime, because it can be changed into another prime (405609101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202804560 + 202804561.

It is an arithmetic number, because the mean of its divisors is an integer number (202804561).

Almost surely, 2^405609121 is an apocalyptic number.

It is an amenable number.

405609121 is a deficient number, since it is larger than the sum of its proper divisors (1).

405609121 is an equidigital number, since it uses as much as digits as its factorization.

405609121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 405609121 is about 20139.7398443972. The cubic root of 405609121 is about 740.2343554050.

The spelling of 405609121 in words is "four hundred five million, six hundred nine thousand, one hundred twenty-one".