21010002021220 has 48 divisors (see below), whose sum is σ = 44274881569968. Its totient is φ = 8374695114240.

The previous prime is 21010002021209. The next prime is 21010002021221. The reversal of 21010002021220 is 2212020001012.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 1030013890816 + 19979988130404 = 1014896^2 + 4469898^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21010002021220.

It is not an unprimeable number, because it can be changed into a prime (21010002021221) 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, 83068150 + ... + 83320690.

It is an arithmetic number, because the mean of its divisors is an integer number (922393366041).

Almost surely, 2^{21010002021220} is an apocalyptic number.

21010002021220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21010002021220 is an abundant number, since it is smaller than the sum of its proper divisors (23264879548748).

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

21010002021220 is a wasteful number, since it uses less digits than its factorization.

21010002021220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 267040 (or 267038 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21010002021220 its reverse (2212020001012), we get a palindrome (23222022022232).

The spelling of 21010002021220 in words is "twenty-one trillion, ten billion, two million, twenty-one thousand, two hundred twenty".