18519864 has 128 divisors (see below), whose sum is σ = 54432000. Its totient is φ = 5196800.

The previous prime is 18519859. The next prime is 18519887. The reversal of 18519864 is 46891581.

It is a super-3 number, since 3×18519864³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 313867 + ... + 313925.

It is an arithmetic number, because the mean of its divisors is an integer number (425250).

Almost surely, 2^18519864 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 18519864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27216000).

18519864 is an abundant number, since it is smaller than the sum of its proper divisors (35912136).

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

18519864 is a wasteful number, since it uses less digits than its factorization.

18519864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149 (or 145 counting only the distinct ones).

The product of its digits is 69120, while the sum is 42.

The square root of 18519864 is about 4303.4711571010. The cubic root of 18519864 is about 264.5732492957.

The spelling of 18519864 in words is "eighteen million, five hundred nineteen thousand, eight hundred sixty-four".