1666745907 has 24 divisors (see below), whose sum is σ = 2302504848. Its totient is φ = 1072431360.

The previous prime is 1666745893. The next prime is 1666745953. The reversal of 1666745907 is 7095476661.

It is a happy number.

It is not a de Polignac number, because 1666745907 - 2⁴ = 1666745891 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1666745907.

It is not an unprimeable number, because it can be changed into a prime (1666745957) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1778343 + ... + 1779279.

It is an arithmetic number, because the mean of its divisors is an integer number (95937702).

Almost surely, 2^1666745907 is an apocalyptic number.

1666745907 is a deficient number, since it is larger than the sum of its proper divisors (635758941).

1666745907 is an equidigital number, since it uses as much as digits as its factorization.

1666745907 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1619 (or 1588 counting only the distinct ones).

The product of its (nonzero) digits is 1905120, while the sum is 51.

The square root of 1666745907 is about 40825.7995267698. The cubic root of 1666745907 is about 1185.6498911596.

The spelling of 1666745907 in words is "one billion, six hundred sixty-six million, seven hundred forty-five thousand, nine hundred seven".