13645112125921 has 4 divisors (see below), whose sum is σ = 13645129598100. Its totient is φ = 13645094653744.

The previous prime is 13645112125889. The next prime is 13645112125949. The reversal of 13645112125921 is 12952121154631.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7244920506321 + 6400191619600 = 2691639^2 + 2529860^2 .

It is a cyclic number.

It is not a de Polignac number, because 13645112125921 - 2⁵ = 13645112125889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13645112195921) 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, 7507006 + ... + 9145783.

It is an arithmetic number, because the mean of its divisors is an integer number (3411282399525).

Almost surely, 2^{13645112125921} is an apocalyptic number.

It is an amenable number.

13645112125921 is a deficient number, since it is larger than the sum of its proper divisors (17472179).

13645112125921 is an equidigital number, since it uses as much as digits as its factorization.

13645112125921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17472178.

The product of its digits is 129600, while the sum is 43.

The spelling of 13645112125921 in words is "thirteen trillion, six hundred forty-five billion, one hundred twelve million, one hundred twenty-five thousand, nine hundred twenty-one".