21348005544 has 160 divisors (see below), whose sum is σ = 64351405800. Its totient is φ = 6587412480.

The previous prime is 21348005537. The next prime is 21348005557. The reversal of 21348005544 is 44550084312.

It is a happy number.

21348005544 is a `hidden beast` number, since 2 + 1 + 34 + 80 + 0 + 5 + 544 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 13101549444 + 8246456100 = 114462^2 + 90810^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21348005499 and 21348005508.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 656092 + ... + 687860.

Almost surely, 2^21348005544 is an apocalyptic number.

21348005544 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21348005544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32175702900).

21348005544 is an abundant number, since it is smaller than the sum of its proper divisors (43003400256).

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

21348005544 is a wasteful number, since it uses less digits than its factorization.

21348005544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31865 (or 31852 counting only the distinct ones).

The product of its (nonzero) digits is 76800, while the sum is 36.

Adding to 21348005544 its reverse (44550084312), we get a palindrome (65898089856).

The spelling of 21348005544 in words is "twenty-one billion, three hundred forty-eight million, five thousand, five hundred forty-four".