20021223210 has 128 divisors (see below), whose sum is σ = 52455997440. Its totient is φ = 4871923200.

The previous prime is 20021223193. The next prime is 20021223239. The reversal of 20021223210 is 1232212002.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 20021223210.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3937870 + ... + 3942950.

It is an arithmetic number, because the mean of its divisors is an integer number (409812480).

Almost surely, 2^20021223210 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20021223210, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26227998720).

20021223210 is an abundant number, since it is smaller than the sum of its proper divisors (32434774230).

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

20021223210 is a wasteful number, since it uses less digits than its factorization.

20021223210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5364.

The product of its (nonzero) digits is 96, while the sum is 15.

Adding to 20021223210 its reverse (1232212002), we get a palindrome (21253435212).

The spelling of 20021223210 in words is "twenty billion, twenty-one million, two hundred twenty-three thousand, two hundred ten".