21513345144 has 32 divisors (see below), whose sum is σ = 53795826000. Its totient is φ = 7169453312.

The previous prime is 21513345097. The next prime is 21513345167. The reversal of 21513345144 is 44154331512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4162 + ... + 207470.

Almost surely, 2^21513345144 is an apocalyptic number.

21513345144 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21513345144 is an abundant number, since it is smaller than the sum of its proper divisors (32282480856).

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

21513345144 is a wasteful number, since it uses less digits than its factorization.

21513345144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207727 (or 207723 counting only the distinct ones).

The product of its digits is 28800, while the sum is 33.

Adding to 21513345144 its reverse (44154331512), we get a palindrome (65667676656).

The spelling of 21513345144 in words is "twenty-one billion, five hundred thirteen million, three hundred forty-five thousand, one hundred forty-four".