221038020 has 216 divisors, whose sum is σ = 821620800. Its totient is φ = 47827584.

The previous prime is 221038007. The next prime is 221038021. The reversal of 221038020 is 20830122.

It is a happy number.

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 = 221037984 and 221038002.

It is not an unprimeable number, because it can be changed into a prime (221038021) by changing a digit.

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 71 ways as a sum of consecutive naturals, for example, 166921 + ... + 168239.

It is an arithmetic number, because the mean of its divisors is an integer number (3803800).

Almost surely, 2^221038020 is an apocalyptic number.

221038020 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 221038020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (410810400).

221038020 is an abundant number, since it is smaller than the sum of its proper divisors (600582780).

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

221038020 is a wasteful number, since it uses less digits than its factorization.

221038020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1367 (or 1355 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 221038020 is about 14867.3474433068. The cubic root of 221038020 is about 604.6290283184.

Adding to 221038020 its reverse (20830122), we get a palindrome (241868142).

The spelling of 221038020 in words is "two hundred twenty-one million, thirty-eight thousand, twenty".