10001321220 has 96 divisors (see below), whose sum is σ = 30594485376. Its totient is φ = 2420992000.

The previous prime is 10001321191. The next prime is 10001321249. The reversal of 10001321220 is 2212310001.

It is an interprime number because it is at equal distance from previous prime (10001321191) and next prime (10001321249).

It is a super-2 number, since 2×10001321220² (a number of 21 digits) contains 22 as substring.

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 = 10001321196 and 10001321205.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 451852 + ... + 473468.

It is an arithmetic number, because the mean of its divisors is an integer number (318692556).

Almost surely, 2^10001321220 is an apocalyptic number.

10001321220 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 10001321220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15297242688).

10001321220 is an abundant number, since it is smaller than the sum of its proper divisors (20593164156).

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

10001321220 is a wasteful number, since it uses less digits than its factorization.

10001321220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22341 (or 22339 counting only the distinct ones).

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

Adding to 10001321220 its reverse (2212310001), we get a palindrome (12213631221).

The spelling of 10001321220 in words is "ten billion, one million, three hundred twenty-one thousand, two hundred twenty".