18816753838661 has 4 divisors (see below), whose sum is σ = 18848809637952. Its totient is φ = 18784698039372.

The previous prime is 18816753838639. The next prime is 18816753838697. The reversal of 18816753838661 is 16683835761881.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18816753838661 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 (18816753838361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16027898765 + ... + 16027899938.

It is an arithmetic number, because the mean of its divisors is an integer number (4712202409488).

Almost surely, 2^{18816753838661} is an apocalyptic number.

It is an amenable number.

18816753838661 is a deficient number, since it is larger than the sum of its proper divisors (32055799291).

18816753838661 is an equidigital number, since it uses as much as digits as its factorization.

18816753838661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32055799290.

The product of its digits is 278691840, while the sum is 71.

The spelling of 18816753838661 in words is "eighteen trillion, eight hundred sixteen billion, seven hundred fifty-three million, eight hundred thirty-eight thousand, six hundred sixty-one".