21120121210000 has 50 divisors (see below), whose sum is σ = 51133925485742. Its totient is φ = 8448048480000.

The previous prime is 21120121209997. The next prime is 21120121210037. The reversal of 21120121210000 is 1212102112.

It can be written as a sum of positive squares in 5 ways, for example, as 3649460046736 + 17470661163264 = 1910356^2 + 4179792^2 .

It is a tau number, because it is divible by the number of its divisors (50).

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1055996061 + ... + 1056016060.

Almost surely, 2^{21120121210000} is an apocalyptic number.

21120121210000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21120121210000 is an abundant number, since it is smaller than the sum of its proper divisors (30013804275742).

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

21120121210000 is an equidigital number, since it uses as much as digits as its factorization.

21120121210000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2112012149 (or 2112012128 counting only the distinct ones).

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

Adding to 21120121210000 its reverse (1212102112), we get a palindrome (21121333312112).

The spelling of 21120121210000 in words is "twenty-one trillion, one hundred twenty billion, one hundred twenty-one million, two hundred ten thousand".