18551226540 has 576 divisors, whose sum is σ = 71583740928. Its totient is φ = 3535257600.

The previous prime is 18551226521. The next prime is 18551226583. The reversal of 18551226540 is 4562215581.

It is a super-2 number, since 2×18551226540² (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 191 ways as a sum of consecutive naturals, for example, 22540569 + ... + 22541391.

It is an arithmetic number, because the mean of its divisors is an integer number (124277328).

Almost surely, 2^18551226540 is an apocalyptic number.

18551226540 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 18551226540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35791870464).

18551226540 is an abundant number, since it is smaller than the sum of its proper divisors (53032514388).

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

18551226540 is a wasteful number, since it uses less digits than its factorization.

18551226540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 918 (or 909 counting only the distinct ones).

The product of its (nonzero) digits is 96000, while the sum is 39.

The spelling of 18551226540 in words is "eighteen billion, five hundred fifty-one million, two hundred twenty-six thousand, five hundred forty".