21525115305 has 16 divisors (see below), whose sum is σ = 34447907520. Its totient is φ = 11477487168.

The previous prime is 21525115291. The next prime is 21525115307. The reversal of 21525115305 is 50351152512.

It is not a de Polignac number, because 21525115305 - 2⁷ = 21525115177 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21525115307) 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, 90790 + ... + 226479.

It is an arithmetic number, because the mean of its divisors is an integer number (2152994220).

Almost surely, 2^21525115305 is an apocalyptic number.

It is an amenable number.

21525115305 is a deficient number, since it is larger than the sum of its proper divisors (12922792215).

21525115305 is a wasteful number, since it uses less digits than its factorization.

21525115305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321800.

The product of its (nonzero) digits is 7500, while the sum is 30.

Adding to 21525115305 its reverse (50351152512), we get a palindrome (71876267817).

The spelling of 21525115305 in words is "twenty-one billion, five hundred twenty-five million, one hundred fifteen thousand, three hundred five".