21213020210 has 16 divisors (see below), whose sum is σ = 38577081816. Its totient is φ = 8397731328.

The previous prime is 21213020207. The next prime is 21213020219. The reversal of 21213020210 is 1202031212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 19866056809 + 1346963401 = 140947^2 + 36701^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21213020219) 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, 10933577 + ... + 10935516.

Almost surely, 2^21213020210 is an apocalyptic number.

21213020210 is a deficient number, since it is larger than the sum of its proper divisors (17364061606).

21213020210 is a wasteful number, since it uses less digits than its factorization.

21213020210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21869197.

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 21213020210 its reverse (1202031212), we get a palindrome (22415051422).

The spelling of 21213020210 in words is "twenty-one billion, two hundred thirteen million, twenty thousand, two hundred ten".