1243565012161 has 4 divisors (see below), whose sum is σ = 1297633056192. Its totient is φ = 1189496968132.

The previous prime is 1243565012113. The next prime is 1243565012167. The reversal of 1243565012161 is 1612105653421.

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 not a de Polignac number, because 1243565012161 - 2³¹ = 1241417528513 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1243565012161.

It is not an unprimeable number, because it can be changed into a prime (1243565012167) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27034021981 + ... + 27034022026.

It is an arithmetic number, because the mean of its divisors is an integer number (324408264048).

Almost surely, 2^{1243565012161} is an apocalyptic number.

It is an amenable number.

1243565012161 is a deficient number, since it is larger than the sum of its proper divisors (54068044031).

1243565012161 is an equidigital number, since it uses as much as digits as its factorization.

1243565012161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54068044030.

The product of its (nonzero) digits is 43200, while the sum is 37.

The spelling of 1243565012161 in words is "one trillion, two hundred forty-three billion, five hundred sixty-five million, twelve thousand, one hundred sixty-one".