21535445123355 has 16 divisors (see below), whose sum is σ = 34457777471520. Its totient is φ = 11485215641088.

The previous prime is 21535445123327. The next prime is 21535445123359. The reversal of 21535445123355 is 55332154453512.

It is not a de Polignac number, because 21535445123355 - 2⁵ = 21535445123323 is a prime.

It is a super-2 number, since 2×21535445123355² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21535445123359) 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, 21691492 + ... + 22662561.

It is an arithmetic number, because the mean of its divisors is an integer number (2153611091970).

Almost surely, 2^{21535445123355} is an apocalyptic number.

21535445123355 is a deficient number, since it is larger than the sum of its proper divisors (12922332348165).

21535445123355 is a wasteful number, since it uses less digits than its factorization.

21535445123355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44386430.

The product of its digits is 5400000, while the sum is 48.

Adding to 21535445123355 its reverse (55332154453512), we get a palindrome (76867599576867).

The spelling of 21535445123355 in words is "twenty-one trillion, five hundred thirty-five billion, four hundred forty-five million, one hundred twenty-three thousand, three hundred fifty-five".