21203032122 has 64 divisors (see below), whose sum is σ = 48005084160. Its totient is φ = 6935406192.

The previous prime is 21203032099. The next prime is 21203032127. The reversal of 21203032122 is 22123030212.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21203032095 and 21203032104.

It is not an unprimeable number, because it can be changed into a prime (21203032127) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 940393 + ... + 962675.

It is an arithmetic number, because the mean of its divisors is an integer number (750079440).

Almost surely, 2^21203032122 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21203032122, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24002542080).

21203032122 is an abundant number, since it is smaller than the sum of its proper divisors (26802052038).

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

21203032122 is a wasteful number, since it uses less digits than its factorization.

21203032122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22624 (or 22618 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 21203032122 its reverse (22123030212), we get a palindrome (43326062334).

The spelling of 21203032122 in words is "twenty-one billion, two hundred three million, thirty-two thousand, one hundred twenty-two".