221131020 has 48 divisors (see below), whose sum is σ = 675456768. Its totient is φ = 53607360.

The previous prime is 221130977. The next prime is 221131073. The reversal of 221131020 is 20131122.

221131020 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 221130987 and 221131005.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 166864 + ... + 168183.

It is an arithmetic number, because the mean of its divisors is an integer number (14072016).

Almost surely, 2^221131020 is an apocalyptic number.

221131020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221131020 is an abundant number, since it is smaller than the sum of its proper divisors (454325748).

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

221131020 is a wasteful number, since it uses less digits than its factorization.

221131020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 335070 (or 335068 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 221131020 is about 14870.4747738598. The cubic root of 221131020 is about 604.7138140570.

Adding to 221131020 its reverse (20131122), we get a palindrome (241262142).

The spelling of 221131020 in words is "two hundred twenty-one million, one hundred thirty-one thousand, twenty".