21013210 has 32 divisors (see below), whose sum is σ = 38972160. Its totient is φ = 8154432.

The previous prime is 21013189. The next prime is 21013217. The reversal of 21013210 is 1231012.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is not an unprimeable number, because it can be changed into a prime (21013217) 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, 52732 + ... + 53128.

It is an arithmetic number, because the mean of its divisors is an integer number (1217880).

Almost surely, 2^21013210 is an apocalyptic number.

21013210 is a deficient number, since it is larger than the sum of its proper divisors (17958950).

21013210 is a wasteful number, since it uses less digits than its factorization.

21013210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 550.

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 21013210 is about 4584.0167975259. The cubic root of 21013210 is about 275.9502553351.

Adding to 21013210 its reverse (1231012), we get a palindrome (22244222).

The spelling of 21013210 in words is "twenty-one million, thirteen thousand, two hundred ten".