21571703136 has 96 divisors (see below), whose sum is σ = 62980092000. Its totient is φ = 7183411200.

The previous prime is 21571703117. The next prime is 21571703137. The reversal of 21571703136 is 63130717512.

21571703136 is a `hidden beast` number, since 2 + 1 + 571 + 70 + 3 + 13 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21571703136.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21571703137) 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, 894436 + ... + 918236.

It is an arithmetic number, because the mean of its divisors is an integer number (656042625).

Almost surely, 2^21571703136 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21571703136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31490046000).

21571703136 is an abundant number, since it is smaller than the sum of its proper divisors (41408388864).

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

21571703136 is a wasteful number, since it uses less digits than its factorization.

21571703136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24869 (or 24855 counting only the distinct ones).

The product of its (nonzero) digits is 26460, while the sum is 36.

The spelling of 21571703136 in words is "twenty-one billion, five hundred seventy-one million, seven hundred three thousand, one hundred thirty-six".