21010001002220 has 96 divisors (see below), whose sum is σ = 45703469790720. Its totient is φ = 8103359416320.

The previous prime is 21010001002187. The next prime is 21010001002229. The reversal of 21010001002220 is 2220010001012.

It is a happy number.

It is a super-2 number, since 2×21010001002220² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21010001002229) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2459319269 + ... + 2459327811.

It is an arithmetic number, because the mean of its divisors is an integer number (476077810320).

Almost surely, 2^{21010001002220} is an apocalyptic number.

21010001002220 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 21010001002220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22851734895360).

21010001002220 is an abundant number, since it is smaller than the sum of its proper divisors (24693468788500).

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

21010001002220 is a wasteful number, since it uses less digits than its factorization.

21010001002220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13755 (or 13753 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21010001002220 its reverse (2220010001012), we get a palindrome (23230011003232).

The spelling of 21010001002220 in words is "twenty-one trillion, ten billion, one million, two thousand, two hundred twenty".