21344354556 has 96 divisors (see below), whose sum is σ = 60615475200. Its totient is φ = 5706415104.

The previous prime is 21344354513. The next prime is 21344354557. The reversal of 21344354556 is 65545344312.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21344354557) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 203845 + ... + 290243.

It is an arithmetic number, because the mean of its divisors is an integer number (631411200).

Almost surely, 2^21344354556 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 21344354556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30307737600).

21344354556 is an abundant number, since it is smaller than the sum of its proper divisors (39271120644).

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

21344354556 is a wasteful number, since it uses less digits than its factorization.

21344354556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86603 (or 86601 counting only the distinct ones).

The product of its digits is 864000, while the sum is 42.

Adding to 21344354556 its reverse (65545344312), we get a palindrome (86889698868).

The spelling of 21344354556 in words is "twenty-one billion, three hundred forty-four million, three hundred fifty-four thousand, five hundred fifty-six".