21540683136 has 128 divisors (see below), whose sum is σ = 69238056960. Its totient is φ = 5792440320.

The previous prime is 21540683089. The next prime is 21540683137. The reversal of 21540683136 is 63138604512.

It is a tau number, because it is divible by the number of its divisors (128).

It is a junction number, because it is equal to n+sod(n) for n = 21540683094 and 21540683103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21540683137) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 190000 + ... + 281391.

It is an arithmetic number, because the mean of its divisors is an integer number (540922320).

Almost surely, 2^21540683136 is an apocalyptic number.

It is an amenable number.

21540683136 is an abundant number, since it is smaller than the sum of its proper divisors (47697373824).

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

21540683136 is a wasteful number, since it uses less digits than its factorization.

21540683136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 471432 (or 471420 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 39.

The spelling of 21540683136 in words is "twenty-one billion, five hundred forty million, six hundred eighty-three thousand, one hundred thirty-six".