161778470777 has 16 divisors (see below), whose sum is σ = 201772603392. Its totient is φ = 126014415120.

The previous prime is 161778470773. The next prime is 161778470797. The reversal of 161778470777 is 777074877161.

It is not a de Polignac number, because 161778470777 - 2² = 161778470773 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161778470773) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 179633 + ... + 596510.

It is an arithmetic number, because the mean of its divisors is an integer number (12610787712).

Almost surely, 2^161778470777 is an apocalyptic number.

It is an amenable number.

161778470777 is a deficient number, since it is larger than the sum of its proper divisors (39994132615).

161778470777 is a wasteful number, since it uses less digits than its factorization.

161778470777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 778868.

The product of its (nonzero) digits is 22588608, while the sum is 62.

The spelling of 161778470777 in words is "one hundred sixty-one billion, seven hundred seventy-eight million, four hundred seventy thousand, seven hundred seventy-seven".