18911563227648 has 1080 divisors, whose sum is σ = 72797352638868. Its totient is φ = 4694111944704.

The previous prime is 18911563227587. The next prime is 18911563227653. The reversal of 18911563227648 is 84672236511981.

It is a happy number.

18911563227648 is a `hidden beast` number, since 1 + 8 + 9 + 1 + 1 + 563 + 2 + 2 + 7 + 64 + 8 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 837093245184 + 18074469982464 = 914928^2 + 4251408^2 .

It is a super-2 number, since 2×18911563227648² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 648685840 + ... + 648714992.

Almost surely, 2^{18911563227648} is an apocalyptic number.

18911563227648 is a gapful number since it is divisible by the number (18) 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 18911563227648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36398676319434).

18911563227648 is an abundant number, since it is smaller than the sum of its proper divisors (53885789411220).

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

18911563227648 is a wasteful number, since it uses less digits than its factorization.

18911563227648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29234 (or 29195 counting only the distinct ones).

The product of its digits is 34836480, while the sum is 63.

The spelling of 18911563227648 in words is "eighteen trillion, nine hundred eleven billion, five hundred sixty-three million, two hundred twenty-seven thousand, six hundred forty-eight".