18919424205 has 32 divisors (see below), whose sum is σ = 36692219520. Its totient is φ = 9173053440.

The previous prime is 18919424201. The next prime is 18919424233. The reversal of 18919424205 is 50242491981.

It is a happy number.

18919424205 is a `hidden beast` number, since 1 + 8 + 9 + 19 + 424 + 205 = 666.

It is not a de Polignac number, because 18919424205 - 2² = 18919424201 is a prime.

It is a super-2 number, since 2×18919424205² (a number of 21 digits) contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18919424201) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6368692 + ... + 6371661.

It is an arithmetic number, because the mean of its divisors is an integer number (1146631860).

Almost surely, 2^18919424205 is an apocalyptic number.

18919424205 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18919424205 is a deficient number, since it is larger than the sum of its proper divisors (17772795315).

18919424205 is a wasteful number, since it uses less digits than its factorization.

18919424205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12740378 (or 12740372 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 45.

The spelling of 18919424205 in words is "eighteen billion, nine hundred nineteen million, four hundred twenty-four thousand, two hundred five".