1666790117 has 2 divisors, whose sum is σ = 1666790118. Its totient is φ = 1666790116.

The previous prime is 1666790101. The next prime is 1666790137. The reversal of 1666790117 is 7110976661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1517803681 + 148986436 = 38959^2 + 12206^2 .

It is a cyclic number.

It is not a de Polignac number, because 1666790117 - 2⁴ = 1666790101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1666790137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833395058 + 833395059.

It is an arithmetic number, because the mean of its divisors is an integer number (833395059).

Almost surely, 2^1666790117 is an apocalyptic number.

It is an amenable number.

1666790117 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666790117 is an equidigital number, since it uses as much as digits as its factorization.

1666790117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 95256, while the sum is 44.

The square root of 1666790117 is about 40826.3409700159. The cubic root of 1666790117 is about 1185.6603740849.

The spelling of 1666790117 in words is "one billion, six hundred sixty-six million, seven hundred ninety thousand, one hundred seventeen".