13865826561 has 4 divisors (see below), whose sum is σ = 18487768752. Its totient is φ = 9243884372.

The previous prime is 13865826551. The next prime is 13865826577. The reversal of 13865826561 is 16562856831.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 13865826561 - 2⁶ = 13865826497 is a prime.

It is a super-2 number, since 2×13865826561² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (13865826551) 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, 2310971091 + ... + 2310971096.

It is an arithmetic number, because the mean of its divisors is an integer number (4621942188).

Almost surely, 2^13865826561 is an apocalyptic number.

It is an amenable number.

13865826561 is a deficient number, since it is larger than the sum of its proper divisors (4621942191).

13865826561 is an equidigital number, since it uses as much as digits as its factorization.

13865826561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4621942190.

The product of its digits is 2073600, while the sum is 51.

The spelling of 13865826561 in words is "thirteen billion, eight hundred sixty-five million, eight hundred twenty-six thousand, five hundred sixty-one".