21700210 has 32 divisors (see below), whose sum is σ = 44957952. Its totient is φ = 7387200.

The previous prime is 21700187. The next prime is 21700219. The reversal of 21700210 is 1200712.

It is a super-2 number, since 2×21700210² = 941798228088200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21700219) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 9544 + ... + 11596.

It is an arithmetic number, because the mean of its divisors is an integer number (1404936).

Almost surely, 2^21700210 is an apocalyptic number.

21700210 is an abundant number, since it is smaller than the sum of its proper divisors (23257742).

21700210 is a wasteful number, since it uses less digits than its factorization.

21700210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2218.

The product of its (nonzero) digits is 28, while the sum is 13.

The square root of 21700210 is about 4658.3484197728. The cubic root of 21700210 is about 278.9253449789.

Adding to 21700210 its reverse (1200712), we get a palindrome (22900922).

The spelling of 21700210 in words is "twenty-one million, seven hundred thousand, two hundred ten".