21736540784 has 40 divisors (see below), whose sum is σ = 48556877280. Its totient is φ = 9233215488.

The previous prime is 21736540769. The next prime is 21736540789. The reversal of 21736540784 is 48704563712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21736540789) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 846089 + ... + 871400.

It is an arithmetic number, because the mean of its divisors is an integer number (1213921932).

Almost surely, 2^21736540784 is an apocalyptic number.

It is an amenable number.

21736540784 is an abundant number, since it is smaller than the sum of its proper divisors (26820336496).

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

21736540784 is a wasteful number, since it uses less digits than its factorization.

21736540784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1717617 (or 1717611 counting only the distinct ones).

The product of its (nonzero) digits is 1128960, while the sum is 47.

The spelling of 21736540784 in words is "twenty-one billion, seven hundred thirty-six million, five hundred forty thousand, seven hundred eighty-four".