18591973440 has 224 divisors, whose sum is σ = 60000587136. Its totient is φ = 4876861440.

The previous prime is 18591973429. The next prime is 18591973469. The reversal of 18591973440 is 4437919581.

It is a super-2 number, since 2×18591973440² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28126710 + ... + 28127370.

It is an arithmetic number, because the mean of its divisors is an integer number (267859764).

Almost surely, 2^18591973440 is an apocalyptic number.

18591973440 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 18591973440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30000293568).

18591973440 is an abundant number, since it is smaller than the sum of its proper divisors (41408613696).

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

18591973440 is a wasteful number, since it uses less digits than its factorization.

18591973440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1117 (or 1107 counting only the distinct ones).

The product of its (nonzero) digits is 1088640, while the sum is 51.

The spelling of 18591973440 in words is "eighteen billion, five hundred ninety-one million, nine hundred seventy-three thousand, four hundred forty".