18516811950 has 384 divisors, whose sum is σ = 66112435200. Its totient is φ = 3700753920.

The previous prime is 18516811921. The next prime is 18516811967. The reversal of 18516811950 is 5911861581.

18516811950 is a `hidden beast` number, since 1 + 8 + 516 + 81 + 1 + 9 + 50 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 18516811896 and 18516811905.

It is a congruent number.

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, 2330184 + ... + 2338116.

It is an arithmetic number, because the mean of its divisors is an integer number (172167800).

Almost surely, 2^18516811950 is an apocalyptic number.

18516811950 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18516811950, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33056217600).

18516811950 is an abundant number, since it is smaller than the sum of its proper divisors (47595623250).

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

18516811950 is a wasteful number, since it uses less digits than its factorization.

18516811950 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7993 (or 7982 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 45.

The spelling of 18516811950 in words is "eighteen billion, five hundred sixteen million, eight hundred eleven thousand, nine hundred fifty".