20421220110 has 64 divisors (see below), whose sum is σ = 49786562304. Its totient is φ = 5359622400.

The previous prime is 20421220109. The next prime is 20421220133. The reversal of 20421220110 is 1102212402.

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 20421220110.

It is a congruent number.

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, 2651365 + ... + 2659055.

It is an arithmetic number, because the mean of its divisors is an integer number (777915036).

Almost surely, 2^20421220110 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20421220110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24893281152).

20421220110 is an abundant number, since it is smaller than the sum of its proper divisors (29365342194).

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

20421220110 is a wasteful number, since it uses less digits than its factorization.

20421220110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9089.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 20421220110 its reverse (1102212402), we get a palindrome (21523432512).

The spelling of 20421220110 in words is "twenty billion, four hundred twenty-one million, two hundred twenty thousand, one hundred ten".