171887053661 has 2 divisors, whose sum is σ = 171887053662. Its totient is φ = 171887053660.

The previous prime is 171887053651. The next prime is 171887053727. The reversal of 171887053661 is 166350788171.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 101000653636 + 70886400025 = 317806^2 + 266245^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-171887053661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (171887053651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85943526830 + 85943526831.

It is an arithmetic number, because the mean of its divisors is an integer number (85943526831).

Almost surely, 2^171887053661 is an apocalyptic number.

It is an amenable number.

171887053661 is a deficient number, since it is larger than the sum of its proper divisors (1).

171887053661 is an equidigital number, since it uses as much as digits as its factorization.

171887053661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1693440, while the sum is 53.

The spelling of 171887053661 in words is "one hundred seventy-one billion, eight hundred eighty-seven million, fifty-three thousand, six hundred sixty-one".