1668520533507 has 4 divisors (see below), whose sum is σ = 2224694044680. Its totient is φ = 1112347022336.

The previous prime is 1668520533499. The next prime is 1668520533517. The reversal of 1668520533507 is 7053350258661.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1668520533507 - 2³ = 1668520533499 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1668520533507.

It is not an unprimeable number, because it can be changed into a prime (1668520533517) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 278086755582 + ... + 278086755587.

It is an arithmetic number, because the mean of its divisors is an integer number (556173511170).

Almost surely, 2^{1668520533507} is an apocalyptic number.

1668520533507 is a deficient number, since it is larger than the sum of its proper divisors (556173511173).

1668520533507 is an equidigital number, since it uses as much as digits as its factorization.

1668520533507 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 556173511172.

The product of its (nonzero) digits is 4536000, while the sum is 51.

The spelling of 1668520533507 in words is "one trillion, six hundred sixty-eight billion, five hundred twenty million, five hundred thirty-three thousand, five hundred seven".