1666842501849 has 32 divisors (see below), whose sum is σ = 2570952130560. Its totient is φ = 940906255872.

The previous prime is 1666842501809. The next prime is 1666842501917. The reversal of 1666842501849 is 9481052486661.

It is not a de Polignac number, because 1666842501849 - 2⁸ = 1666842501593 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1666842501792 and 1666842501801.

It is not an unprimeable number, because it can be changed into a prime (1666842501809) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 257529 + ... + 1843910.

It is an arithmetic number, because the mean of its divisors is an integer number (80342254080).

Almost surely, 2^{1666842501849} is an apocalyptic number.

It is an amenable number.

1666842501849 is a deficient number, since it is larger than the sum of its proper divisors (904109628711).

1666842501849 is a wasteful number, since it uses less digits than its factorization.

1666842501849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2101909.

The product of its (nonzero) digits is 19906560, while the sum is 60.

The spelling of 1666842501849 in words is "one trillion, six hundred sixty-six billion, eight hundred forty-two million, five hundred one thousand, eight hundred forty-nine".