161537077777 has 2 divisors, whose sum is σ = 161537077778. Its totient is φ = 161537077776.

The previous prime is 161537077763. The next prime is 161537077781. The reversal of 161537077777 is 777770735161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 139361102721 + 22175975056 = 373311^2 + 148916^2 .

It is a cyclic number.

It is not a de Polignac number, because 161537077777 - 2⁷ = 161537077649 is a prime.

It is not a weakly prime, because it can be changed into another prime (161537027777) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80768538888 + 80768538889.

It is an arithmetic number, because the mean of its divisors is an integer number (80768538889).

Almost surely, 2^161537077777 is an apocalyptic number.

It is an amenable number.

161537077777 is a deficient number, since it is larger than the sum of its proper divisors (1).

161537077777 is an equidigital number, since it uses as much as digits as its factorization.

161537077777 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10588410, while the sum is 58.

The spelling of 161537077777 in words is "one hundred sixty-one billion, five hundred thirty-seven million, seventy-seven thousand, seven hundred seventy-seven".