21005202 has 32 divisors (see below), whose sum is σ = 43505280. Its totient is φ = 6756480.

The previous prime is 21005191. The next prime is 21005209. The reversal of 21005202 is 20250012.

It is a super-2 number, since 2×21005202² = 882437022121608, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21005209) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24924 + ... + 25752.

It is an arithmetic number, because the mean of its divisors is an integer number (1359540).

Almost surely, 2^21005202 is an apocalyptic number.

21005202 is an abundant number, since it is smaller than the sum of its proper divisors (22500078).

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

21005202 is a wasteful number, since it uses less digits than its factorization.

21005202 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 978.

The product of its (nonzero) digits is 40, while the sum is 12.

The square root of 21005202 is about 4583.1432445430. The cubic root of 21005202 is about 275.9151965884.

Adding to 21005202 its reverse (20250012), we get a palindrome (41255214).

The spelling of 21005202 in words is "twenty-one million, five thousand, two hundred two".