21534042325 has 24 divisors (see below), whose sum is σ = 26892606888. Its totient is φ = 17104846080.

The previous prime is 21534042317. The next prime is 21534042347. The reversal of 21534042325 is 52324043512.

It can be written as a sum of positive squares in 12 ways, for example, as 89075844 + 21444966481 = 9438^2 + 146441^2 .

It is not a de Polignac number, because 21534042325 - 2³ = 21534042317 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2023719 + ... + 2034331.

It is an arithmetic number, because the mean of its divisors is an integer number (1120525287).

Almost surely, 2^21534042325 is an apocalyptic number.

21534042325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21534042325 is a deficient number, since it is larger than the sum of its proper divisors (5358564563).

21534042325 is a wasteful number, since it uses less digits than its factorization.

21534042325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11193 (or 11188 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 31.

Adding to 21534042325 its reverse (52324043512), we get a palindrome (73858085837).

The spelling of 21534042325 in words is "twenty-one billion, five hundred thirty-four million, forty-two thousand, three hundred twenty-five".