12521717357 has 4 divisors (see below), whose sum is σ = 12554411520. Its totient is φ = 12489023196.

The previous prime is 12521717321. The next prime is 12521717359. The reversal of 12521717357 is 75371712521.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 75371712521 = 7 ⋅10767387503.

It is a cyclic number.

It is not a de Polignac number, because 12521717357 - 2³² = 8226750061 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12521717359) 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, 16346507 + ... + 16347272.

It is an arithmetic number, because the mean of its divisors is an integer number (3138602880).

Almost surely, 2^12521717357 is an apocalyptic number.

It is an amenable number.

12521717357 is a deficient number, since it is larger than the sum of its proper divisors (32694163).

12521717357 is an equidigital number, since it uses as much as digits as its factorization.

12521717357 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32694162.

The product of its digits is 102900, while the sum is 41.

The spelling of 12521717357 in words is "twelve billion, five hundred twenty-one million, seven hundred seventeen thousand, three hundred fifty-seven".