21120121011210 has 32 divisors (see below), whose sum is σ = 54587389691520. Its totient is φ = 5198799018048.

The previous prime is 21120121011083. The next prime is 21120121011221. The reversal of 21120121011210 is 1211012102112.

It is a happy number.

It is a super-2 number, since 2×21120121011210² (a number of 27 digits) contains 22 as substring.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21120121011210.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27077077830 + ... + 27077078609.

It is an arithmetic number, because the mean of its divisors is an integer number (1705855927860).

Almost surely, 2^{21120121011210} is an apocalyptic number.

21120121011210 is an abundant number, since it is smaller than the sum of its proper divisors (33467268680310).

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

21120121011210 is a wasteful number, since it uses less digits than its factorization.

21120121011210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54154156462.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21120121011210 its reverse (1211012102112), we get a palindrome (22331133113322).

The spelling of 21120121011210 in words is "twenty-one trillion, one hundred twenty billion, one hundred twenty-one million, eleven thousand, two hundred ten".