166661310414251 has 2 divisors, whose sum is σ = 166661310414252. Its totient is φ = 166661310414250.

The previous prime is 166661310414239. The next prime is 166661310414253. The reversal of 166661310414251 is 152414013166661.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166661310414251 is a prime.

It is a Sophie Germain prime.

Together with 166661310414253, 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 = 166661310414196 and 166661310414205.

It is not a weakly prime, because it can be changed into another prime (166661310414253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83330655207125 + 83330655207126.

It is an arithmetic number, because the mean of its divisors is an integer number (83330655207126).

Almost surely, 2^{166661310414251} is an apocalyptic number.

166661310414251 is a deficient number, since it is larger than the sum of its proper divisors (1).

166661310414251 is an equidigital number, since it uses as much as digits as its factorization.

166661310414251 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 622080, while the sum is 47.

The spelling of 166661310414251 in words is "one hundred sixty-six trillion, six hundred sixty-one billion, three hundred ten million, four hundred fourteen thousand, two hundred fifty-one".