18451689984 has 480 divisors, whose sum is σ = 66490744320. Its totient is φ = 4796153856.

The previous prime is 18451689983. The next prime is 18451690009. The reversal of 18451689984 is 48998615481.

18451689984 is a `hidden beast` number, since 18 + 451 + 6 + 8 + 99 + 84 = 666.

It is a super-4 number, since 4×18451689984⁴ (a number of 42 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (18451689983) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 33126634 + ... + 33127190.

It is an arithmetic number, because the mean of its divisors is an integer number (138522384).

Almost surely, 2^18451689984 is an apocalyptic number.

18451689984 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18451689984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33245372160).

18451689984 is an abundant number, since it is smaller than the sum of its proper divisors (48039054336).

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

18451689984 is a wasteful number, since it uses less digits than its factorization.

18451689984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 680 (or 661 counting only the distinct ones).

The product of its digits is 19906560, while the sum is 63.

The spelling of 18451689984 in words is "eighteen billion, four hundred fifty-one million, six hundred eighty-nine thousand, nine hundred eighty-four".