21100202 has 4 divisors (see below), whose sum is σ = 31650306. Its totient is φ = 10550100.

The previous prime is 21100193. The next prime is 21100207. The reversal of 21100202 is 20200112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 16736281 + 4363921 = 4091^2 + 2089^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21100202.

It is not an unprimeable number, because it can be changed into a prime (21100207) 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 as a sum of consecutive naturals, namely, 5275049 + ... + 5275052.

Almost surely, 2^21100202 is an apocalyptic number.

21100202 is a deficient number, since it is larger than the sum of its proper divisors (10550104).

21100202 is a wasteful number, since it uses less digits than its factorization.

21100202 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10550103.

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

The square root of 21100202 is about 4593.4956188071. The cubic root of 21100202 is about 276.3305306329.

Adding to 21100202 its reverse (20200112), we get a palindrome (41300314).

The spelling of 21100202 in words is "twenty-one million, one hundred thousand, two hundred two".