12261358561 has 4 divisors (see below), whose sum is σ = 12434053824. Its totient is φ = 12088663300.

The previous prime is 12261358531. The next prime is 12261358573. The reversal of 12261358561 is 16585316221.

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: 16585316221 = 83 ⋅199823087.

It is a cyclic number.

It is not a de Polignac number, because 12261358561 - 2⁷ = 12261358433 is a prime.

It is a super-2 number, since 2×12261358561² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12261358531) 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, 86347525 + ... + 86347666.

It is an arithmetic number, because the mean of its divisors is an integer number (3108513456).

Almost surely, 2^12261358561 is an apocalyptic number.

It is an amenable number.

12261358561 is a deficient number, since it is larger than the sum of its proper divisors (172695263).

12261358561 is an equidigital number, since it uses as much as digits as its factorization.

12261358561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172695262.

The product of its digits is 86400, while the sum is 40.

The spelling of 12261358561 in words is "twelve billion, two hundred sixty-one million, three hundred fifty-eight thousand, five hundred sixty-one".