21020202 has 32 divisors (see below), whose sum is σ = 53385600. Its totient is φ = 6005664.

The previous prime is 21020161. The next prime is 21020227. The reversal of 21020202 is 20202012.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27427 + ... + 28182.

It is an arithmetic number, because the mean of its divisors is an integer number (1668300).

Almost surely, 2^21020202 is an apocalyptic number.

21020202 is an abundant number, since it is smaller than the sum of its proper divisors (32365398).

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

21020202 is a wasteful number, since it uses less digits than its factorization.

21020202 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55627 (or 55621 counting only the distinct ones).

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

The square root of 21020202 is about 4584.7793840053. The cubic root of 21020202 is about 275.9808587860.

Adding to 21020202 its reverse (20202012), we get a palindrome (41222214).

The spelling of 21020202 in words is "twenty-one million, twenty thousand, two hundred two".