18911770240 has 128 divisors (see below), whose sum is σ = 51465870720. Its totient is φ = 6577950720.

The previous prime is 18911770237. The next prime is 18911770247. The reversal of 18911770240 is 4207711981.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×18911770240² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 18911770193 and 18911770202.

It is not an unprimeable number, because it can be changed into a prime (18911770247) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 103522 + ... + 220318.

It is an arithmetic number, because the mean of its divisors is an integer number (402077115).

Almost surely, 2^18911770240 is an apocalyptic number.

18911770240 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 18911770240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25732935360).

18911770240 is an abundant number, since it is smaller than the sum of its proper divisors (32554100480).

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

18911770240 is a wasteful number, since it uses less digits than its factorization.

18911770240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116850 (or 116838 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 40.

The spelling of 18911770240 in words is "eighteen billion, nine hundred eleven million, seven hundred seventy thousand, two hundred forty".