21120645312020 has 24 divisors (see below), whose sum is σ = 44353558972800. Its totient is φ = 8448219302432.

The previous prime is 21120645312001. The next prime is 21120645312023. The reversal of 21120645312020 is 2021354602112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120645312023) 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, 2254961 + ... + 6879399.

It is an arithmetic number, because the mean of its divisors is an integer number (1848064957200).

Almost surely, 2^{21120645312020} is an apocalyptic number.

21120645312020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21120645312020 is an abundant number, since it is smaller than the sum of its proper divisors (23232913660780).

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

21120645312020 is a wasteful number, since it uses less digits than its factorization.

21120645312020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4852807 (or 4852805 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 29.

Adding to 21120645312020 its reverse (2021354602112), we get a palindrome (23141999914132).

The spelling of 21120645312020 in words is "twenty-one trillion, one hundred twenty billion, six hundred forty-five million, three hundred twelve thousand, twenty".