18938277565440 has 352 divisors, whose sum is σ = 61229177518080. Its totient is φ = 4995600777216.

The previous prime is 18938277565421. The next prime is 18938277565483. The reversal of 18938277565440 is 4456577283981.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1529865171 + ... + 1529877549.

It is an arithmetic number, because the mean of its divisors is an integer number (173946527040).

It is a 1-persistent number, because it is pandigital, but 2⋅18938277565440 = 37876555130880 is not.

Almost surely, 2^{18938277565440} is an apocalyptic number.

18938277565440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18938277565440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30614588759040).

18938277565440 is an abundant number, since it is smaller than the sum of its proper divisors (42290899952640).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18938277565440 is a wasteful number, since it uses less digits than its factorization.

18938277565440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13477 (or 13459 counting only the distinct ones).

The product of its (nonzero) digits is 406425600, while the sum is 69.

The spelling of 18938277565440 in words is "eighteen trillion, nine hundred thirty-eight billion, two hundred seventy-seven million, five hundred sixty-five thousand, four hundred forty".