1656161161661 has 2 divisors, whose sum is σ = 1656161161662. Its totient is φ = 1656161161660.

The previous prime is 1656161161619. The next prime is 1656161161691. The reversal of 1656161161661 is 1661611616561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1525980913636 + 130180248025 = 1235306^2 + 360805^2 .

It is a cyclic number.

It is not a de Polignac number, because 1656161161661 - 2³⁴ = 1638981292477 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1656161161691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 828080580830 + 828080580831.

It is an arithmetic number, because the mean of its divisors is an integer number (828080580831).

Almost surely, 2^{1656161161661} is an apocalyptic number.

It is an amenable number.

1656161161661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1656161161661 is an equidigital number, since it uses as much as digits as its factorization.

1656161161661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 233280, while the sum is 47.

The spelling of 1656161161661 in words is "one trillion, six hundred fifty-six billion, one hundred sixty-one million, one hundred sixty-one thousand, six hundred sixty-one".