161558779 has 2 divisors, whose sum is σ = 161558780. Its totient is φ = 161558778.

The previous prime is 161558743. The next prime is 161558801. The reversal of 161558779 is 977855161.

It is a happy number.

161558779 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 161558779 - 2²⁷ = 27341051 is a prime.

It is a super-2 number, since 2×161558779² = 52202478143941682, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (161552779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80779389 + 80779390.

It is an arithmetic number, because the mean of its divisors is an integer number (80779390).

Almost surely, 2^161558779 is an apocalyptic number.

161558779 is a deficient number, since it is larger than the sum of its proper divisors (1).

161558779 is an equidigital number, since it uses as much as digits as its factorization.

161558779 is an evil number, because the sum of its binary digits is even.

The product of its digits is 529200, while the sum is 49.

The square root of 161558779 is about 12710.5774455766. The cubic root of 161558779 is about 544.6408193629.

The spelling of 161558779 in words is "one hundred sixty-one million, five hundred fifty-eight thousand, seven hundred seventy-nine".