18361967550 has 24 divisors (see below), whose sum is σ = 45537679896. Its totient is φ = 4896524640.

The previous prime is 18361967513. The next prime is 18361967557. The reversal of 18361967550 is 5576916381.

It is a junction number, because it is equal to n+sod(n) for n = 18361967493 and 18361967502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18361967557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 61206409 + ... + 61206708.

It is an arithmetic number, because the mean of its divisors is an integer number (1897403329).

Almost surely, 2^18361967550 is an apocalyptic number.

18361967550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18361967550 is an abundant number, since it is smaller than the sum of its proper divisors (27175712346).

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

18361967550 is a wasteful number, since it uses less digits than its factorization.

18361967550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122413132 (or 122413127 counting only the distinct ones).

The product of its (nonzero) digits is 1360800, while the sum is 51.

The spelling of 18361967550 in words is "eighteen billion, three hundred sixty-one million, nine hundred sixty-seven thousand, five hundred fifty".