409321891 has 16 divisors (see below), whose sum is σ = 451680768. Its totient is φ = 367848000.

The previous prime is 409321867. The next prime is 409321909. The reversal of 409321891 is 198123904.

It is a cyclic number.

It is not a de Polignac number, because 409321891 - 2⁹ = 409321379 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 409321891.

It is not an unprimeable number, because it can be changed into a prime (409321841) 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 in 15 ways as a sum of consecutive naturals, for example, 436375 + ... + 437311.

It is an arithmetic number, because the mean of its divisors is an integer number (28230048).

Almost surely, 2^409321891 is an apocalyptic number.

409321891 is a deficient number, since it is larger than the sum of its proper divisors (42358877).

409321891 is a wasteful number, since it uses less digits than its factorization.

409321891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1362.

The product of its (nonzero) digits is 15552, while the sum is 37.

The square root of 409321891 is about 20231.7050937384. The cubic root of 409321891 is about 742.4860936000.

The spelling of 409321891 in words is "four hundred nine million, three hundred twenty-one thousand, eight hundred ninety-one".