1666319993501 has 8 divisors (see below), whose sum is σ = 1743280285824. Its totient is φ = 1591089146080.

The previous prime is 1666319993483. The next prime is 1666319993531. The reversal of 1666319993501 is 1053999136661.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1666319993501 is a prime.

It is a super-3 number, since 3×1666319993501³ (a number of 38 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666319993531) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 432359255 + ... + 432363108.

It is an arithmetic number, because the mean of its divisors is an integer number (217910035728).

Almost surely, 2^{1666319993501} is an apocalyptic number.

It is an amenable number.

1666319993501 is a deficient number, since it is larger than the sum of its proper divisors (76960292323).

1666319993501 is an equidigital number, since it uses as much as digits as its factorization.

1666319993501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 864722451.

The product of its (nonzero) digits is 7085880, while the sum is 59.

The spelling of 1666319993501 in words is "one trillion, six hundred sixty-six billion, three hundred nineteen million, nine hundred ninety-three thousand, five hundred one".