221231409 has 8 divisors (see below), whose sum is σ = 337114560. Its totient is φ = 126417936.

The previous prime is 221231393. The next prime is 221231429. The reversal of 221231409 is 904132122.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 221231409 - 2⁴ = 221231393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221231429) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5267394 + ... + 5267435.

It is an arithmetic number, because the mean of its divisors is an integer number (42139320).

Almost surely, 2^221231409 is an apocalyptic number.

It is an amenable number.

221231409 is a deficient number, since it is larger than the sum of its proper divisors (115883151).

221231409 is a wasteful number, since it uses less digits than its factorization.

221231409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10534839.

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 221231409 is about 14873.8498378866. The cubic root of 221231409 is about 604.8053094833.

It can be divided in two parts, 22123 and 1409, that added together give a palindrome (23532).

The spelling of 221231409 in words is "two hundred twenty-one million, two hundred thirty-one thousand, four hundred nine".