221403420 has 144 divisors (see below), whose sum is σ = 772262400. Its totient is φ = 50295168.

The previous prime is 221403401. The next prime is 221403439. The reversal of 221403420 is 24304122.

221403420 is a `hidden beast` number, since 221 + 403 + 42 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (221403401) and next prime (221403439).

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

It is a junction number, because it is equal to n+sod(n) for n = 221403393 and 221403402.

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 250299 + ... + 251181.

Almost surely, 2^221403420 is an apocalyptic number.

221403420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221403420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (386131200).

221403420 is an abundant number, since it is smaller than the sum of its proper divisors (550858980).

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

221403420 is a wasteful number, since it uses less digits than its factorization.

221403420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1104 (or 1099 counting only the distinct ones).

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

The square root of 221403420 is about 14879.6310438129. The cubic root of 221403420 is about 604.9620175139.

Adding to 221403420 its reverse (24304122), we get a palindrome (245707542).

The spelling of 221403420 in words is "two hundred twenty-one million, four hundred three thousand, four hundred twenty".