21203031344 has 120 divisors (see below), whose sum is σ = 47613723360. Its totient is φ = 9121812480.

The previous prime is 21203031341. The next prime is 21203031383. The reversal of 21203031344 is 44313030212.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is not an unprimeable number, because it can be changed into a prime (21203031341) 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, 4316762 + ... + 4321670.

It is an arithmetic number, because the mean of its divisors is an integer number (396781028).

Almost surely, 2^21203031344 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21203031344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23806861680).

21203031344 is an abundant number, since it is smaller than the sum of its proper divisors (26410692016).

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

21203031344 is a wasteful number, since it uses less digits than its factorization.

21203031344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5059 (or 5042 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 23.

Adding to 21203031344 its reverse (44313030212), we get a palindrome (65516061556).

The spelling of 21203031344 in words is "twenty-one billion, two hundred three million, thirty-one thousand, three hundred forty-four".