21520004332135 has 4 divisors (see below), whose sum is σ = 25824005198568. Its totient is φ = 17216003465704.

The previous prime is 21520004332133. The next prime is 21520004332139. The reversal of 21520004332135 is 53123340002512.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21520004332135 - 2¹ = 21520004332133 is a prime.

It is a super-2 number, since 2×21520004332135² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21520004332097 and 21520004332106.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21520004332133) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2152000433209 + ... + 2152000433218.

It is an arithmetic number, because the mean of its divisors is an integer number (6456001299642).

Almost surely, 2^{21520004332135} is an apocalyptic number.

21520004332135 is a deficient number, since it is larger than the sum of its proper divisors (4304000866433).

21520004332135 is an equidigital number, since it uses as much as digits as its factorization.

21520004332135 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4304000866432.

The product of its (nonzero) digits is 21600, while the sum is 31.

Adding to 21520004332135 its reverse (53123340002512), we get a palindrome (74643344334647).

The spelling of 21520004332135 in words is "twenty-one trillion, five hundred twenty billion, four million, three hundred thirty-two thousand, one hundred thirty-five".