18211225005 has 16 divisors (see below), whose sum is σ = 32375511360. Its totient is φ = 9712653264.

The previous prime is 18211224943. The next prime is 18211225037. The reversal of 18211225005 is 50052211281.

It is a happy number.

18211225005 is a `hidden beast` number, since 18 + 21 + 122 + 500 + 5 = 666.

It is not a de Polignac number, because 18211225005 - 2¹⁶ = 18211159469 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 18211225005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 67448847 + ... + 67449116.

It is an arithmetic number, because the mean of its divisors is an integer number (2023469460).

Almost surely, 2^18211225005 is an apocalyptic number.

18211225005 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18211225005 is a deficient number, since it is larger than the sum of its proper divisors (14164286355).

18211225005 is a wasteful number, since it uses less digits than its factorization.

18211225005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134897977 (or 134897971 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 27.

Adding to 18211225005 its reverse (50052211281), we get a palindrome (68263436286).

The spelling of 18211225005 in words is "eighteen billion, two hundred eleven million, two hundred twenty-five thousand, five".