20328381 has 8 divisors (see below), whose sum is σ = 30116160. Its totient is φ = 13552236.

The previous prime is 20328367. The next prime is 20328419. The reversal of 20328381 is 18382302.

It is not a de Polignac number, because 20328381 - 2⁵ = 20328349 is a prime.

It is a super-2 number, since 2×20328381² = 826486148162322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 752903 = 20328381 / (2 + 0 + 3 + 2 + 8 + 3 + 8 + 1).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20328331) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 376425 + ... + 376478.

It is an arithmetic number, because the mean of its divisors is an integer number (3764520).

Almost surely, 2^20328381 is an apocalyptic number.

It is an amenable number.

20328381 is a deficient number, since it is larger than the sum of its proper divisors (9787779).

20328381 is an equidigital number, since it uses as much as digits as its factorization.

20328381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 752912 (or 752906 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 20328381 is about 4508.7005888615. The cubic root of 20328381 is about 272.9193095666.

The spelling of 20328381 in words is "twenty million, three hundred twenty-eight thousand, three hundred eighty-one".