161256337777 has 4 divisors (see below), whose sum is σ = 161257216576. Its totient is φ = 161255458980.

The previous prime is 161256337751. The next prime is 161256337789. The reversal of 161256337777 is 777733652161.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 161256337777 - 2¹⁹ = 161255813489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161256337717) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47853 + ... + 569914.

It is an arithmetic number, because the mean of its divisors is an integer number (40314304144).

Almost surely, 2^161256337777 is an apocalyptic number.

It is an amenable number.

161256337777 is a deficient number, since it is larger than the sum of its proper divisors (878799).

161256337777 is an equidigital number, since it uses as much as digits as its factorization.

161256337777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 878798.

The product of its digits is 7779240, while the sum is 55.

The spelling of 161256337777 in words is "one hundred sixty-one billion, two hundred fifty-six million, three hundred thirty-seven thousand, seven hundred seventy-seven".