18872424 has 48 divisors (see below), whose sum is σ = 51962820. Its totient is φ = 6186240.

The previous prime is 18872419. The next prime is 18872429. The reversal of 18872424 is 42427881.

It is an interprime number because it is at equal distance from previous prime (18872419) and next prime (18872429).

It can be written as a sum of positive squares in 2 ways, for example, as 17388900 + 1483524 = 4170^2 + 1218^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (18872429) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2244 + ... + 6540.

Almost surely, 2^18872424 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 18872424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25981410).

18872424 is an abundant number, since it is smaller than the sum of its proper divisors (33090396).

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

18872424 is a wasteful number, since it uses less digits than its factorization.

18872424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4370 (or 4363 counting only the distinct ones).

The product of its digits is 28672, while the sum is 36.

The square root of 18872424 is about 4344.2403248439. The cubic root of 18872424 is about 266.2415880434.

The spelling of 18872424 in words is "eighteen million, eight hundred seventy-two thousand, four hundred twenty-four".