166649543407 has 2 divisors, whose sum is σ = 166649543408. Its totient is φ = 166649543406.

The previous prime is 166649543363. The next prime is 166649543443. The reversal of 166649543407 is 704345946661.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166649543407 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166649553407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83324771703 + 83324771704.

It is an arithmetic number, because the mean of its divisors is an integer number (83324771704).

Almost surely, 2^166649543407 is an apocalyptic number.

166649543407 is a deficient number, since it is larger than the sum of its proper divisors (1).

166649543407 is an equidigital number, since it uses as much as digits as its factorization.

166649543407 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13063680, while the sum is 55.

The spelling of 166649543407 in words is "one hundred sixty-six billion, six hundred forty-nine million, five hundred forty-three thousand, four hundred seven".