1668387185517 has 32 divisors (see below), whose sum is σ = 2412357494400. Its totient is φ = 1019535816960.

The previous prime is 1668387185503. The next prime is 1668387185533. The reversal of 1668387185517 is 7155817838661.

It is not a de Polignac number, because 1668387185517 - 2⁴ = 1668387185501 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1668387185557) 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, 22806523 + ... + 22879559.

It is an arithmetic number, because the mean of its divisors is an integer number (75386171700).

Almost surely, 2^{1668387185517} is an apocalyptic number.

It is an amenable number.

1668387185517 is a deficient number, since it is larger than the sum of its proper divisors (743970308883).

1668387185517 is a wasteful number, since it uses less digits than its factorization.

1668387185517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77133.

The product of its digits is 67737600, while the sum is 66.

The spelling of 1668387185517 in words is "one trillion, six hundred sixty-eight billion, three hundred eighty-seven million, one hundred eighty-five thousand, five hundred seventeen".