221131420 has 24 divisors (see below), whose sum is σ = 468978048. Its totient is φ = 87576000.

The previous prime is 221131411. The next prime is 221131429. The reversal of 221131420 is 24131122.

221131420 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (221131411) and next prime (221131429).

It is a super-2 number, since 2×221131420² = 97798209822432800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 221131394 and 221131403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221131429) 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, 52716 + ... + 56755.

It is an arithmetic number, because the mean of its divisors is an integer number (19540752).

Almost surely, 2^221131420 is an apocalyptic number.

221131420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221131420 is an abundant number, since it is smaller than the sum of its proper divisors (247846628).

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

221131420 is a wasteful number, since it uses less digits than its factorization.

221131420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109581 (or 109579 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 221131420 is about 14870.4882233234. The cubic root of 221131420 is about 604.7141786755.

Adding to 221131420 its reverse (24131122), we get a palindrome (245262542).

The spelling of 221131420 in words is "two hundred twenty-one million, one hundred thirty-one thousand, four hundred twenty".