221121020 has 12 divisors (see below), whose sum is σ = 464354184. Its totient is φ = 88448400.

The previous prime is 221121013. The next prime is 221121053. The reversal of 221121020 is 20121122.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 221120992 and 221121010.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5528006 + ... + 5528045.

It is an arithmetic number, because the mean of its divisors is an integer number (38696182).

Almost surely, 2^221121020 is an apocalyptic number.

221121020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221121020 is an abundant number, since it is smaller than the sum of its proper divisors (243233164).

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

221121020 is a wasteful number, since it uses less digits than its factorization.

221121020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11056060 (or 11056058 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 221121020 is about 14870.1385333157. The cubic root of 221121020 is about 604.7046984517.

Adding to 221121020 its reverse (20121122), we get a palindrome (241242142).

It can be divided in two parts, 22112 and 1020, that added together give a palindrome (23132).

The spelling of 221121020 in words is "two hundred twenty-one million, one hundred twenty-one thousand, twenty".