21290210 has 16 divisors (see below), whose sum is σ = 38382336. Its totient is φ = 8502768.

The previous prime is 21290189. The next prime is 21290219. The reversal of 21290210 is 1209212.

It is a zygodrome in base 3.

It is not an unprimeable number, because it can be changed into a prime (21290219) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7397 + ... + 9863.

It is an arithmetic number, because the mean of its divisors is an integer number (2398896).

Almost surely, 2^21290210 is an apocalyptic number.

21290210 is a deficient number, since it is larger than the sum of its proper divisors (17092126).

21290210 is a wasteful number, since it uses less digits than its factorization.

21290210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3337.

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 21290210 is about 4614.1315542581. The cubic root of 21290210 is about 277.1575083732.

Adding to 21290210 its reverse (1209212), we get a palindrome (22499422).

The spelling of 21290210 in words is "twenty-one million, two hundred ninety thousand, two hundred ten".