1161610111505 has 4 divisors (see below), whose sum is σ = 1393932133812. Its totient is φ = 929288089200.

The previous prime is 1161610111463. The next prime is 1161610111507. The reversal of 1161610111505 is 5051110161611.

It is a happy number.

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 215651570689 + 945958540816 = 464383^2 + 972604^2 .

It is not a de Polignac number, because 1161610111505 - 2¹⁶ = 1161610045969 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1161610111507) 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, 116161011146 + ... + 116161011155.

It is an arithmetic number, because the mean of its divisors is an integer number (348483033453).

Almost surely, 2^{1161610111505} is an apocalyptic number.

It is an amenable number.

1161610111505 is a deficient number, since it is larger than the sum of its proper divisors (232322022307).

1161610111505 is an equidigital number, since it uses as much as digits as its factorization.

1161610111505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232322022306.

The product of its (nonzero) digits is 900, while the sum is 29.

The spelling of 1161610111505 in words is "one trillion, one hundred sixty-one billion, six hundred ten million, one hundred eleven thousand, five hundred five".