1668503686837 has 4 divisors (see below), whose sum is σ = 1796850124300. Its totient is φ = 1540157249376.

The previous prime is 1668503686741. The next prime is 1668503686841. The reversal of 1668503686837 is 7386863058661.

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

It can be written as a sum of positive squares in 2 ways, for example, as 89143447761 + 1579360239076 = 298569^2 + 1256726^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1668503686837 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 (1668503686037) 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, 64173218712 + ... + 64173218737.

It is an arithmetic number, because the mean of its divisors is an integer number (449212531075).

Almost surely, 2^{1668503686837} is an apocalyptic number.

It is an amenable number.

1668503686837 is a deficient number, since it is larger than the sum of its proper divisors (128346437463).

1668503686837 is a wasteful number, since it uses less digits than its factorization.

1668503686837 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128346437462.

The product of its (nonzero) digits is 209018880, while the sum is 67.

The spelling of 1668503686837 in words is "one trillion, six hundred sixty-eight billion, five hundred three million, six hundred eighty-six thousand, eight hundred thirty-seven".