21211020121210 has 32 divisors (see below), whose sum is σ = 38559571849872. Its totient is φ = 8400029836800.

The previous prime is 21211020121147. The next prime is 21211020121211. The reversal of 21211020121210 is 1212102011212.

It can be written as a sum of positive squares in 8 ways, for example, as 12823410598441 + 8387609522769 = 3580979^2 + 2896137^2 .

It is not an unprimeable number, because it can be changed into a prime (21211020121211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22790964 + ... + 23703376.

Almost surely, 2^{21211020121210} is an apocalyptic number.

21211020121210 is a deficient number, since it is larger than the sum of its proper divisors (17348551728662).

21211020121210 is a wasteful number, since it uses less digits than its factorization.

21211020121210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 935538.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21211020121210 its reverse (1212102011212), we get a palindrome (22423122132422).

The spelling of 21211020121210 in words is "twenty-one trillion, two hundred eleven billion, twenty million, one hundred twenty-one thousand, two hundred ten".