21534210325 has 6 divisors (see below), whose sum is σ = 26702420834. Its totient is φ = 17227368240.

The previous prime is 21534210319. The next prime is 21534210331. The reversal of 21534210325 is 52301243512.

It is an interprime number because it is at equal distance from previous prime (21534210319) and next prime (21534210331).

It can be written as a sum of positive squares in 3 ways, for example, as 28281124 + 21505929201 = 5318^2 + 146649^2 .

It is not a de Polignac number, because 21534210325 - 2¹³ = 21534202133 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21534210293 and 21534210302.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 430684182 + ... + 430684231.

Almost surely, 2^21534210325 is an apocalyptic number.

21534210325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21534210325 is a deficient number, since it is larger than the sum of its proper divisors (5168210509).

21534210325 is an equidigital number, since it uses as much as digits as its factorization.

21534210325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 861368423 (or 861368418 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 28.

Adding to 21534210325 its reverse (52301243512), we get a palindrome (73835453837).

The spelling of 21534210325 in words is "twenty-one billion, five hundred thirty-four million, two hundred ten thousand, three hundred twenty-five".