21841588521 has 15 divisors (see below), whose sum is σ = 32629545223. Its totient is φ = 14560172280.

The previous prime is 21841588519. The next prime is 21841588577. The reversal of 21841588521 is 12588514812.

The square root of 21841588521 is 147789.

It is a perfect power (a square), and thus also a powerful number.

21841588521 is a `hidden beast` number, since 2 + 1 + 8 + 41 + 5 + 88 + 521 = 666.

It can be written as a sum of positive squares in only one way, i.e., 214944921 + 21626643600 = 14661^2 + 147060^2 .

It is not a de Polignac number, because 21841588521 - 2¹ = 21841588519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21841588591) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 1321891 + ... + 1338311.

Almost surely, 2^21841588521 is an apocalyptic number.

21841588521 is the 147789-th square number.

21841588521 is the 73895-th centered octagonal number.

It is an amenable number.

21841588521 is a deficient number, since it is larger than the sum of its proper divisors (10787956702).

21841588521 is an frugal number, since it uses more digits than its factorization.

21841588521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32854 (or 16424 counting only the distinct ones).

The product of its digits is 204800, while the sum is 45.

It can be divided in two parts, 218415 and 88521, that added together give a triangular number (306936 = T₇₈₃).

The spelling of 21841588521 in words is "twenty-one billion, eight hundred forty-one million, five hundred eighty-eight thousand, five hundred twenty-one".