166021564232957 has 2 divisors, whose sum is σ = 166021564232958. Its totient is φ = 166021564232956.

The previous prime is 166021564232947. The next prime is 166021564232959. The reversal of 166021564232957 is 759232465120661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 166021318025476 + 246207481 = 12884926^2 + 15691^2 .

It is a cyclic number.

It is not a de Polignac number, because 166021564232957 - 2¹⁰ = 166021564231933 is a prime.

Together with 166021564232959, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 166021564232896 and 166021564232905.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166021564232959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83010782116478 + 83010782116479.

It is an arithmetic number, because the mean of its divisors is an integer number (83010782116479).

Almost surely, 2^{166021564232957} is an apocalyptic number.

It is an amenable number.

166021564232957 is a deficient number, since it is larger than the sum of its proper divisors (1).

166021564232957 is an equidigital number, since it uses as much as digits as its factorization.

166021564232957 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32659200, while the sum is 59.

The spelling of 166021564232957 in words is "one hundred sixty-six trillion, twenty-one billion, five hundred sixty-four million, two hundred thirty-two thousand, nine hundred fifty-seven".