21290202 has 48 divisors (see below), whose sum is σ = 48589632. Its totient is φ = 6985440.

The previous prime is 21290189. The next prime is 21290219. The reversal of 21290202 is 20209212.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a zygodrome in base 3.

It is an unprimeable number.

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 in 23 ways as a sum of consecutive naturals, for example, 34198 + ... + 34814.

It is an arithmetic number, because the mean of its divisors is an integer number (1012284).

Almost surely, 2^21290202 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21290202, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24294816).

21290202 is an abundant number, since it is smaller than the sum of its proper divisors (27299430).

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

21290202 is an equidigital number, since it uses as much as digits as its factorization.

21290202 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 705 (or 693 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 21290202 is about 4614.1306873560. The cubic root of 21290202 is about 277.1574736584.

Adding to 21290202 its reverse (20209212), we get a palindrome (41499414).

The spelling of 21290202 in words is "twenty-one million, two hundred ninety thousand, two hundred two".