18451891952 has 80 divisors (see below), whose sum is σ = 41191842720. Its totient is φ = 7935667200.

The previous prime is 18451891943. The next prime is 18451891961. The reversal of 18451891952 is 25919815481.

It is an interprime number because it is at equal distance from previous prime (18451891943) and next prime (18451891961).

It is a junction number, because it is equal to n+sod(n) for n = 18451891894 and 18451891903.

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, 202802 + ... + 279342.

It is an arithmetic number, because the mean of its divisors is an integer number (514898034).

Almost surely, 2^18451891952 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18451891952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20595921360).

18451891952 is an abundant number, since it is smaller than the sum of its proper divisors (22739950768).

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

18451891952 is a wasteful number, since it uses less digits than its factorization.

18451891952 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76642 (or 76636 counting only the distinct ones).

The product of its digits is 1036800, while the sum is 53.

The spelling of 18451891952 in words is "eighteen billion, four hundred fifty-one million, eight hundred ninety-one thousand, nine hundred fifty-two".