221203404 has 18 divisors (see below), whose sum is σ = 559153140. Its totient is φ = 73734456.

The previous prime is 221203399. The next prime is 221203421. The reversal of 221203404 is 404302122.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3072234 + ... + 3072305.

Almost surely, 2^221203404 is an apocalyptic number.

It is an amenable number.

221203404 is an abundant number, since it is smaller than the sum of its proper divisors (337949736).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221203404 is a wasteful number, since it uses less digits than its factorization.

221203404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6144549 (or 6144544 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 221203404 is about 14872.9083907620. The cubic root of 221203404 is about 604.7797882617.

Adding to 221203404 its reverse (404302122), we get a palindrome (625505526).

The spelling of 221203404 in words is "two hundred twenty-one million, two hundred three thousand, four hundred four".