161311777 has 4 divisors (see below), whose sum is σ = 175976496. Its totient is φ = 146647060.

The previous prime is 161311769. The next prime is 161311783. The reversal of 161311777 is 777113161.

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 161311777 - 2³ = 161311769 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161311727) 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, 7332343 + ... + 7332364.

It is an arithmetic number, because the mean of its divisors is an integer number (43994124).

Almost surely, 2^161311777 is an apocalyptic number.

It is an amenable number.

161311777 is a deficient number, since it is larger than the sum of its proper divisors (14664719).

161311777 is a wasteful number, since it uses less digits than its factorization.

161311777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14664718.

The product of its digits is 6174, while the sum is 34.

The square root of 161311777 is about 12700.8573332669. The cubic root of 161311777 is about 544.3631165376.

The spelling of 161311777 in words is "one hundred sixty-one million, three hundred eleven thousand, seven hundred seventy-seven".