21231201210 has 16 divisors (see below), whose sum is σ = 50954882976. Its totient is φ = 5661653648.

The previous prime is 21231201191. The next prime is 21231201221. The reversal of 21231201210 is 1210213212.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21231201210.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 353853324 + ... + 353853383.

It is an arithmetic number, because the mean of its divisors is an integer number (3184680186).

Almost surely, 2^21231201210 is an apocalyptic number.

21231201210 is an abundant number, since it is smaller than the sum of its proper divisors (29723681766).

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

21231201210 is a wasteful number, since it uses less digits than its factorization.

21231201210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 707706717.

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21231201210 its reverse (1210213212), we get a palindrome (22441414422).

The spelling of 21231201210 in words is "twenty-one billion, two hundred thirty-one million, two hundred one thousand, two hundred ten".