18673608621551 has 4 divisors (see below), whose sum is σ = 20110040053992. Its totient is φ = 17237177189112.

The previous prime is 18673608621523. The next prime is 18673608621587. The reversal of 18673608621551 is 15512680637681.

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 18673608621551 - 2³⁰ = 18672534879727 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 (18673608621751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 718215716201 + ... + 718215716226.

It is an arithmetic number, because the mean of its divisors is an integer number (5027510013498).

Almost surely, 2^{18673608621551} is an apocalyptic number.

18673608621551 is a deficient number, since it is larger than the sum of its proper divisors (1436431432441).

18673608621551 is a wasteful number, since it uses less digits than its factorization.

18673608621551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1436431432440.

The product of its (nonzero) digits is 14515200, while the sum is 59.

The spelling of 18673608621551 in words is "eighteen trillion, six hundred seventy-three billion, six hundred eight million, six hundred twenty-one thousand, five hundred fifty-one".