18919209357 has 6 divisors (see below), whose sum is σ = 27327746862. Its totient is φ = 12612806232.

The previous prime is 18919209349. The next prime is 18919209367. The reversal of 18919209357 is 75390291981.

18919209357 is a `hidden beast` number, since 1 + 89 + 1 + 9 + 209 + 357 = 666.

It can be written as a sum of positive squares in only one way, i.e., 18467179236 + 452030121 = 135894^2 + 21261^2 .

It is not a de Polignac number, because 18919209357 - 2³ = 18919209349 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18919209317) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1051067178 + ... + 1051067195.

It is an arithmetic number, because the mean of its divisors is an integer number (4554624477).

Almost surely, 2^18919209357 is an apocalyptic number.

It is an amenable number.

18919209357 is a deficient number, since it is larger than the sum of its proper divisors (8408537505).

18919209357 is a wasteful number, since it uses less digits than its factorization.

18919209357 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2102134379 (or 2102134376 counting only the distinct ones).

The product of its (nonzero) digits is 1224720, while the sum is 54.

The spelling of 18919209357 in words is "eighteen billion, nine hundred nineteen million, two hundred nine thousand, three hundred fifty-seven".