221001120 has 144 divisors (see below), whose sum is σ = 759507840. Its totient is φ = 58516992.

The previous prime is 221001119. The next prime is 221001133. The reversal of 221001120 is 21100122.

It is a tau number, because it is divible by the number of its divisors (144).

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 240021 + ... + 240939.

It is an arithmetic number, because the mean of its divisors is an integer number (5274360).

Almost surely, 2^221001120 is an apocalyptic number.

221001120 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 221001120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (379753920).

221001120 is an abundant number, since it is smaller than the sum of its proper divisors (538506720).

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

221001120 is a wasteful number, since it uses less digits than its factorization.

221001120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1107 (or 1096 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 221001120 is about 14866.1064169472. The cubic root of 221001120 is about 604.5953809354.

Adding to 221001120 its reverse (21100122), we get a palindrome (242101242).

It can be divided in two parts, 22100 and 1120, that added together give a triangular number (23220 = T₂₁₅).

The spelling of 221001120 in words is "two hundred twenty-one million, one thousand, one hundred twenty".