21513214944 has 288 divisors, whose sum is σ = 70114131360. Its totient is φ = 6198460416.

The previous prime is 21513214897. The next prime is 21513214967. The reversal of 21513214944 is 44941231512.

It is a tau number, because it is divible by the number of its divisors (288).

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 = 21513214899 and 21513214908.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 14447352 + ... + 14448840.

It is an arithmetic number, because the mean of its divisors is an integer number (243451845).

Almost surely, 2^21513214944 is an apocalyptic number.

21513214944 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 21513214944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35057065680).

21513214944 is an abundant number, since it is smaller than the sum of its proper divisors (48600916416).

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

21513214944 is a wasteful number, since it uses less digits than its factorization.

21513214944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1762 (or 1751 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The spelling of 21513214944 in words is "twenty-one billion, five hundred thirteen million, two hundred fourteen thousand, nine hundred forty-four".