21205520325 has 72 divisors (see below), whose sum is σ = 41585228256. Its totient is φ = 10244016000.

The previous prime is 21205520317. The next prime is 21205520363. The reversal of 21205520325 is 52302550212.

It is not a de Polignac number, because 21205520325 - 2³ = 21205520317 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 670110 + ... + 701040.

Almost surely, 2^21205520325 is an apocalyptic number.

21205520325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21205520325 is a deficient number, since it is larger than the sum of its proper divisors (20379707931).

21205520325 is a wasteful number, since it uses less digits than its factorization.

21205520325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31235 (or 31227 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 27.

The spelling of 21205520325 in words is "twenty-one billion, two hundred five million, five hundred twenty thousand, three hundred twenty-five".