21253125324261 has 8 divisors (see below), whose sum is σ = 28377468700960. Its totient is φ = 14148766081872.

The previous prime is 21253125324259. The next prime is 21253125324293. The reversal of 21253125324261 is 16242352135212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21253125324261 - 2¹ = 21253125324259 is a prime.

It is a super-2 number, since 2×21253125324261² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21253125324161) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4996031095 + ... + 4996035348.

It is an arithmetic number, because the mean of its divisors is an integer number (3547183587620).

Almost surely, 2^{21253125324261} is an apocalyptic number.

It is an amenable number.

21253125324261 is a deficient number, since it is larger than the sum of its proper divisors (7124343376699).

21253125324261 is an equidigital number, since it uses as much as digits as its factorization.

21253125324261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9992067155.

The product of its digits is 172800, while the sum is 39.

Adding to 21253125324261 its reverse (16242352135212), we get a palindrome (37495477459473).

The spelling of 21253125324261 in words is "twenty-one trillion, two hundred fifty-three billion, one hundred twenty-five million, three hundred twenty-four thousand, two hundred sixty-one".