166717087501 has 2 divisors, whose sum is σ = 166717087502. Its totient is φ = 166717087500.

The previous prime is 166717087499. The next prime is 166717087519. The reversal of 166717087501 is 105780717661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 165383742276 + 1333345225 = 406674^2 + 36515^2 .

It is an emirp because it is prime and its reverse (105780717661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166717087501 - 2¹ = 166717087499 is a prime.

Together with 166717087499, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166717087531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83358543750 + 83358543751.

It is an arithmetic number, because the mean of its divisors is an integer number (83358543751).

Almost surely, 2^166717087501 is an apocalyptic number.

It is an amenable number.

166717087501 is a deficient number, since it is larger than the sum of its proper divisors (1).

166717087501 is an equidigital number, since it uses as much as digits as its factorization.

166717087501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 493920, while the sum is 49.

The spelling of 166717087501 in words is "one hundred sixty-six billion, seven hundred seventeen million, eighty-seven thousand, five hundred one".