21533525243355 has 16 divisors (see below), whose sum is σ = 34513352085024. Its totient is φ = 11464642897920.

The previous prime is 21533525243323. The next prime is 21533525243357. The reversal of 21533525243355 is 55334252533512.

It is a happy number.

It is not a de Polignac number, because 21533525243355 - 2⁵ = 21533525243323 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21533525243357) 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, 1243984716 + ... + 1244002025.

It is an arithmetic number, because the mean of its divisors is an integer number (2157084505314).

Almost surely, 2^{21533525243355} is an apocalyptic number.

21533525243355 is a deficient number, since it is larger than the sum of its proper divisors (12979826841669).

21533525243355 is a wasteful number, since it uses less digits than its factorization.

21533525243355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2487987326.

The product of its digits is 8100000, while the sum is 48.

Adding to 21533525243355 its reverse (55334252533512), we get a palindrome (76867777776867).

The spelling of 21533525243355 in words is "twenty-one trillion, five hundred thirty-three billion, five hundred twenty-five million, two hundred forty-three thousand, three hundred fifty-five".