172057661 has 2 divisors, whose sum is σ = 172057662. Its totient is φ = 172057660.

The previous prime is 172057649. The next prime is 172057681. The reversal of 172057661 is 166750271.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 155500900 + 16556761 = 12470^2 + 4069^2 .

It is a cyclic number.

It is not a de Polignac number, because 172057661 - 2¹⁰ = 172056637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172057621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86028830 + 86028831.

It is an arithmetic number, because the mean of its divisors is an integer number (86028831).

Almost surely, 2^172057661 is an apocalyptic number.

It is an amenable number.

172057661 is a deficient number, since it is larger than the sum of its proper divisors (1).

172057661 is an equidigital number, since it uses as much as digits as its factorization.

172057661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17640, while the sum is 35.

The square root of 172057661 is about 13117.0751694118. The cubic root of 172057661 is about 556.1919150559.

The spelling of 172057661 in words is "one hundred seventy-two million, fifty-seven thousand, six hundred sixty-one".