221404020 has 24 divisors (see below), whose sum is σ = 619931424. Its totient is φ = 59041056.

The previous prime is 221404013. The next prime is 221404021. The reversal of 221404020 is 20404122.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221404021) 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, 1844974 + ... + 1845093.

It is an arithmetic number, because the mean of its divisors is an integer number (25830476).

Almost surely, 2^221404020 is an apocalyptic number.

221404020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221404020 is an abundant number, since it is smaller than the sum of its proper divisors (398527404).

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

221404020 is a wasteful number, since it uses less digits than its factorization.

221404020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3690079 (or 3690077 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 15.

The square root of 221404020 is about 14879.6512055895. The cubic root of 221404020 is about 604.9625639928.

Adding to 221404020 its reverse (20404122), we get a palindrome (241808142).

The spelling of 221404020 in words is "two hundred twenty-one million, four hundred four thousand, twenty".