21303455544 has 80 divisors (see below), whose sum is σ = 68193615600. Its totient is φ = 6086700288.

The previous prime is 21303455543. The next prime is 21303455567. The reversal of 21303455544 is 44555430312.

21303455544 is a `hidden beast` number, since 2 + 1 + 30 + 34 + 55 + 544 = 666.

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 = 21303455499 and 21303455508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21303455543) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2343729 + ... + 2352800.

It is an arithmetic number, because the mean of its divisors is an integer number (852420195).

Almost surely, 2^21303455544 is an apocalyptic number.

21303455544 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21303455544 is an abundant number, since it is smaller than the sum of its proper divisors (46890160056).

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

21303455544 is a wasteful number, since it uses less digits than its factorization.

21303455544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4696554 (or 4696541 counting only the distinct ones).

The product of its (nonzero) digits is 144000, while the sum is 36.

Adding to 21303455544 its reverse (44555430312), we get a palindrome (65858885856).

The spelling of 21303455544 in words is "twenty-one billion, three hundred three million, four hundred fifty-five thousand, five hundred forty-four".