221200020 has 36 divisors (see below), whose sum is σ = 670973940. Its totient is φ = 58986624.

The previous prime is 221200009. The next prime is 221200069. The reversal of 221200020 is 20002122.

It can be written as a sum of positive squares in 2 ways, for example, as 171243396 + 49956624 = 13086^2 + 7068^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 221199975 and 221200011.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 614265 + ... + 614624.

It is an arithmetic number, because the mean of its divisors is an integer number (18638165).

Almost surely, 2^221200020 is an apocalyptic number.

221200020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221200020 is an abundant number, since it is smaller than the sum of its proper divisors (449773920).

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

221200020 is a wasteful number, since it uses less digits than its factorization.

221200020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1228904 (or 1228899 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 9.

The square root of 221200020 is about 14872.7946264312. The cubic root of 221200020 is about 604.7767042446.

Adding to 221200020 its reverse (20002122), we get a palindrome (241202142).

The spelling of 221200020 in words is "two hundred twenty-one million, two hundred thousand, twenty".