1666843509253 has 8 divisors (see below), whose sum is σ = 1795347848448. Its totient is φ = 1538379971184.

The previous prime is 1666843509251. The next prime is 1666843509313. The reversal of 1666843509253 is 3529053486661.

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

It is a cyclic number.

It is not a de Polignac number, because 1666843509253 - 2¹ = 1666843509251 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666843509251) 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, 10115401 + ... + 10278862.

It is an arithmetic number, because the mean of its divisors is an integer number (224418481056).

Almost surely, 2^{1666843509253} is an apocalyptic number.

1666843509253 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1666843509253 is a deficient number, since it is larger than the sum of its proper divisors (128504339195).

1666843509253 is a wasteful number, since it uses less digits than its factorization.

1666843509253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20400563.

The product of its (nonzero) digits is 27993600, while the sum is 58.

The spelling of 1666843509253 in words is "one trillion, six hundred sixty-six billion, eight hundred forty-three million, five hundred nine thousand, two hundred fifty-three".