10221211220 has 72 divisors (see below), whose sum is σ = 23810325000. Its totient is φ = 3682609920.

The previous prime is 10221211219. The next prime is 10221211229. The reversal of 10221211220 is 2211212201.

It can be written as a sum of positive squares in 4 ways, for example, as 1736222224 + 8484988996 = 41668^2 + 92114^2 .

It is a junction number, because it is equal to n+sod(n) for n = 10221211195 and 10221211204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10221211229) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 244406 + ... + 283154.

Almost surely, 2^10221211220 is an apocalyptic number.

10221211220 is a gapful number since it is divisible by the number (10) 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 10221211220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11905162500).

10221211220 is an abundant number, since it is smaller than the sum of its proper divisors (13589113780).

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

10221211220 is a wasteful number, since it uses less digits than its factorization.

10221211220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38889 (or 38876 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 10221211220 its reverse (2211212201), we get a palindrome (12432423421).

The spelling of 10221211220 in words is "ten billion, two hundred twenty-one million, two hundred eleven thousand, two hundred twenty".