18451891953 has 36 divisors (see below), whose sum is σ = 30886700208. Its totient is φ = 10525127040.

The previous prime is 18451891943. The next prime is 18451891961. The reversal of 18451891953 is 35919815481.

It is a happy number.

18451891953 is a `hidden beast` number, since 18 + 451 + 8 + 91 + 95 + 3 = 666.

It is not a de Polignac number, because 18451891953 - 2²⁵ = 18418337521 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 18451891953.

It is not an unprimeable number, because it can be changed into a prime (18451891903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 293851 + ... + 351072.

Almost surely, 2^18451891953 is an apocalyptic number.

It is an amenable number.

18451891953 is a deficient number, since it is larger than the sum of its proper divisors (12434808255).

18451891953 is a wasteful number, since it uses less digits than its factorization.

18451891953 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 644974 (or 644954 counting only the distinct ones).

The product of its digits is 1555200, while the sum is 54.

The spelling of 18451891953 in words is "eighteen billion, four hundred fifty-one million, eight hundred ninety-one thousand, nine hundred fifty-three".