21201013020 has 192 divisors, whose sum is σ = 65632799232. Its totient is φ = 5070720000.

The previous prime is 21201013019. The next prime is 21201013027. The reversal of 21201013020 is 2031010212.

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 = 21201012987 and 21201013005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201013027) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 37129335 + ... + 37129905.

It is an arithmetic number, because the mean of its divisors is an integer number (341837496).

Almost surely, 2^21201013020 is an apocalyptic number.

21201013020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21201013020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32816399616).

21201013020 is an abundant number, since it is smaller than the sum of its proper divisors (44431786212).

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

21201013020 is a wasteful number, since it uses less digits than its factorization.

21201013020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1252 (or 1250 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 21201013020 its reverse (2031010212), we get a palindrome (23232023232).

The spelling of 21201013020 in words is "twenty-one billion, two hundred one million, thirteen thousand, twenty".