20181328 has 10 divisors (see below), whose sum is σ = 39101354. Its totient is φ = 10090656.

The previous prime is 20181323. The next prime is 20181347. The reversal of 20181328 is 82318102.

It can be written as a sum of positive squares in only one way, i.e., 13483584 + 6697744 = 3672^2 + 2588^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20181323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630651 + ... + 630682.

Almost surely, 2^20181328 is an apocalyptic number.

It is an amenable number.

20181328 is a deficient number, since it is larger than the sum of its proper divisors (18920026).

20181328 is a wasteful number, since it uses less digits than its factorization.

20181328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1261341 (or 1261335 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 20181328 is about 4492.3632978645. The cubic root of 20181328 is about 272.2596281114.

The spelling of 20181328 in words is "twenty million, one hundred eighty-one thousand, three hundred twenty-eight".