1225782556161 has 4 divisors (see below), whose sum is σ = 1634376741552. Its totient is φ = 817188370772.

The previous prime is 1225782556157. The next prime is 1225782556289. The reversal of 1225782556161 is 1616552875221.

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 1225782556161 - 2² = 1225782556157 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1225782556151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 204297092691 + ... + 204297092696.

It is an arithmetic number, because the mean of its divisors is an integer number (408594185388).

Almost surely, 2^{1225782556161} is an apocalyptic number.

It is an amenable number.

1225782556161 is a deficient number, since it is larger than the sum of its proper divisors (408594185391).

1225782556161 is an equidigital number, since it uses as much as digits as its factorization.

1225782556161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 408594185390.

The product of its digits is 2016000, while the sum is 51.

The spelling of 1225782556161 in words is "one trillion, two hundred twenty-five billion, seven hundred eighty-two million, five hundred fifty-six thousand, one hundred sixty-one".