21121120210 has 16 divisors (see below), whose sum is σ = 39328983000. Its totient is φ = 8157122176.

The previous prime is 21121120187. The next prime is 21121120211. The reversal of 21121120210 is 1202112112.

It can be written as a sum of positive squares in 4 ways, for example, as 20718435721 + 402684489 = 143939^2 + 20067^2 .

It is a super-2 number, since 2×21121120210² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21121120211) 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, 36415435 + ... + 36416014.

Almost surely, 2^21121120210 is an apocalyptic number.

21121120210 is a deficient number, since it is larger than the sum of its proper divisors (18207862790).

21121120210 is a wasteful number, since it uses less digits than its factorization.

21121120210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72831485.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21121120210 its reverse (1202112112), we get a palindrome (22323232322).

The spelling of 21121120210 in words is "twenty-one billion, one hundred twenty-one million, one hundred twenty thousand, two hundred ten".