21210120001020 has 48 divisors (see below), whose sum is σ = 59391909739008. Its totient is φ = 5655691644480.

The previous prime is 21210120000983. The next prime is 21210120001027. The reversal of 21210120001020 is 2010002101212.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 21210120000987 and 21210120001005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210120001027) 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, 9629944 + ... + 11625663.

It is an arithmetic number, because the mean of its divisors is an integer number (1237331452896).

Almost surely, 2^{21210120001020} is an apocalyptic number.

21210120001020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21210120001020 is an abundant number, since it is smaller than the sum of its proper divisors (38181789737988).

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

21210120001020 is a wasteful number, since it uses less digits than its factorization.

21210120001020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21272250 (or 21272248 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21210120001020 its reverse (2010002101212), we get a palindrome (23220122102232).

The spelling of 21210120001020 in words is "twenty-one trillion, two hundred ten billion, one hundred twenty million, one thousand, twenty".