21121021334320 has 40 divisors (see below), whose sum is σ = 49116608121600. Its totient is φ = 8446647928320.

The previous prime is 21121021334279. The next prime is 21121021334323. The reversal of 21121021334320 is 2343312012112.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (21121021334323) 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, 27123141 + ... + 27890980.

It is an arithmetic number, because the mean of its divisors is an integer number (1227915203040).

Almost surely, 2^{21121021334320} is an apocalyptic number.

21121021334320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21121021334320 is an abundant number, since it is smaller than the sum of its proper divisors (27995586787280).

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

21121021334320 is a wasteful number, since it uses less digits than its factorization.

21121021334320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55018933 (or 55018927 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 25.

Adding to 21121021334320 its reverse (2343312012112), we get a palindrome (23464333346432).

The spelling of 21121021334320 in words is "twenty-one trillion, one hundred twenty-one billion, twenty-one million, three hundred thirty-four thousand, three hundred twenty".