409418921 has 2 divisors, whose sum is σ = 409418922. Its totient is φ = 409418920.

The previous prime is 409418909. The next prime is 409418969. The reversal of 409418921 is 129814904.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 302586025 + 106832896 = 17395^2 + 10336^2 .

It is a cyclic number.

It is not a de Polignac number, because 409418921 - 2¹⁸ = 409156777 is a prime.

It is a super-3 number, since 3×409418921³ (a number of 27 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (409418981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 204709460 + 204709461.

It is an arithmetic number, because the mean of its divisors is an integer number (204709461).

Almost surely, 2^409418921 is an apocalyptic number.

It is an amenable number.

409418921 is a deficient number, since it is larger than the sum of its proper divisors (1).

409418921 is an equidigital number, since it uses as much as digits as its factorization.

409418921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20736, while the sum is 38.

The square root of 409418921 is about 20234.1029205646. The cubic root of 409418921 is about 742.5447578895.

The spelling of 409418921 in words is "four hundred nine million, four hundred eighteen thousand, nine hundred twenty-one".