21542145135 has 48 divisors (see below), whose sum is σ = 40117026816. Its totient is φ = 9842371392.

The previous prime is 21542145091. The next prime is 21542145137. The reversal of 21542145135 is 53154124512.

It is not a de Polignac number, because 21542145135 - 2¹¹ = 21542143087 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21542145096 and 21542145105.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21542145137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1509202 + ... + 1523408.

It is an arithmetic number, because the mean of its divisors is an integer number (835771392).

Almost surely, 2^21542145135 is an apocalyptic number.

21542145135 is a deficient number, since it is larger than the sum of its proper divisors (18574881681).

21542145135 is a wasteful number, since it uses less digits than its factorization.

21542145135 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16292 (or 16285 counting only the distinct ones).

The product of its digits is 24000, while the sum is 33.

Adding to 21542145135 its reverse (53154124512), we get a palindrome (74696269647).

The spelling of 21542145135 in words is "twenty-one billion, five hundred forty-two million, one hundred forty-five thousand, one hundred thirty-five".