166666500650506 has 4 divisors (see below), whose sum is σ = 249999750975762. Its totient is φ = 83333250325252.

The previous prime is 166666500650459. The next prime is 166666500650509. The reversal of 166666500650506 is 605056005666661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 128328001958025 + 38338498692481 = 11328195^2 + 6191809^2 .

It is not an unprimeable number, because it can be changed into a prime (166666500650509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41666625162625 + ... + 41666625162628.

Almost surely, 2^{166666500650506} is an apocalyptic number.

166666500650506 is a deficient number, since it is larger than the sum of its proper divisors (83333250325256).

166666500650506 is an equidigital number, since it uses as much as digits as its factorization.

166666500650506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83333250325255.

The product of its (nonzero) digits is 34992000, while the sum is 58.

The spelling of 166666500650506 in words is "one hundred sixty-six trillion, six hundred sixty-six billion, five hundred million, six hundred fifty thousand, five hundred six".