18273756648391 has 4 divisors (see below), whose sum is σ = 18274028593912. Its totient is φ = 18273484702872.

The previous prime is 18273756648349. The next prime is 18273756648403. The reversal of 18273756648391 is 19384665737281.

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 18273756648391 - 2⁹ = 18273756647879 is a prime.

It is a super-2 number, since 2×18273756648391² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18273756648391.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18273756648331) 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, 135871941 + ... + 136006366.

It is an arithmetic number, because the mean of its divisors is an integer number (4568507148478).

Almost surely, 2^{18273756648391} is an apocalyptic number.

18273756648391 is a deficient number, since it is larger than the sum of its proper divisors (271945521).

18273756648391 is an equidigital number, since it uses as much as digits as its factorization.

18273756648391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271945520.

The product of its digits is 365783040, while the sum is 70.

The spelling of 18273756648391 in words is "eighteen trillion, two hundred seventy-three billion, seven hundred fifty-six million, six hundred forty-eight thousand, three hundred ninety-one".