21120020210 has 16 divisors (see below), whose sum is σ = 40252274136. Its totient is φ = 7951066368.

The previous prime is 21120020203. The next prime is 21120020221. The reversal of 21120020210 is 1202002112.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 20081440681 + 1038579529 = 141709^2 + 32227^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21120020191 and 21120020200.

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, 62117537 + ... + 62117876.

Almost surely, 2^21120020210 is an apocalyptic number.

21120020210 is a deficient number, since it is larger than the sum of its proper divisors (19132253926).

21120020210 is a wasteful number, since it uses less digits than its factorization.

21120020210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124235437.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21120020210 its reverse (1202002112), we get a palindrome (22322022322).

The spelling of 21120020210 in words is "twenty-one billion, one hundred twenty million, twenty thousand, two hundred ten".