161861827079 has 4 divisors (see below), whose sum is σ = 161864268384. Its totient is φ = 161859385776.

The previous prime is 161861826977. The next prime is 161861827129. The reversal of 161861827079 is 970728168161.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161861827079 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161861827979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1118342 + ... + 1254755.

It is an arithmetic number, because the mean of its divisors is an integer number (40466067096).

Almost surely, 2^161861827079 is an apocalyptic number.

161861827079 is a deficient number, since it is larger than the sum of its proper divisors (2441305).

161861827079 is an equidigital number, since it uses as much as digits as its factorization.

161861827079 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2441304.

The product of its (nonzero) digits is 2032128, while the sum is 56.

The spelling of 161861827079 in words is "one hundred sixty-one billion, eight hundred sixty-one million, eight hundred twenty-seven thousand, seventy-nine".