18945911556 has 192 divisors, whose sum is σ = 57875005440. Its totient is φ = 5284068480.

The previous prime is 18945911539. The next prime is 18945911561. The reversal of 18945911556 is 65511954981.

It is a happy number.

18945911556 is a `hidden beast` number, since 1 + 89 + 4 + 5 + 9 + 1 + 1 + 556 = 666.

It is a super-2 number, since 2×18945911556² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5913451 + ... + 5916653.

It is an arithmetic number, because the mean of its divisors is an integer number (301432320).

Almost surely, 2^18945911556 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18945911556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28937502720).

18945911556 is an abundant number, since it is smaller than the sum of its proper divisors (38929093884).

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

18945911556 is a wasteful number, since it uses less digits than its factorization.

18945911556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3623 (or 3615 counting only the distinct ones).

The product of its digits is 1944000, while the sum is 54.

The spelling of 18945911556 in words is "eighteen billion, nine hundred forty-five million, nine hundred eleven thousand, five hundred fifty-six".