221200101 has 6 divisors (see below), whose sum is σ = 319511270. Its totient is φ = 147466728.

The previous prime is 221200093. The next prime is 221200121. The reversal of 221200101 is 101002122.

It can be written as a sum of positive squares in only one way, i.e., 121220100 + 99980001 = 11010^2 + 9999^2 .

It is not a de Polignac number, because 221200101 - 2³ = 221200093 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 24577789 = 221200101 / (2 + 2 + 1 + 2 + 0 + 0 + 1 + 0 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221200121) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12288886 + ... + 12288903.

Almost surely, 2^221200101 is an apocalyptic number.

It is an amenable number.

221200101 is a deficient number, since it is larger than the sum of its proper divisors (98311169).

221200101 is a wasteful number, since it uses less digits than its factorization.

221200101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24577795 (or 24577792 counting only the distinct ones).

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

The square root of 221200101 is about 14872.7973495237. The cubic root of 221200101 is about 604.7767780646.

Adding to 221200101 its reverse (101002122), we get a palindrome (322202223).

The spelling of 221200101 in words is "two hundred twenty-one million, two hundred thousand, one hundred one".