20381930 has 16 divisors (see below), whose sum is σ = 37290024. Its totient is φ = 8018880.

The previous prime is 20381909. The next prime is 20381939. The reversal of 20381930 is 3918302.

It can be written as a sum of positive squares in 4 ways, for example, as 16265089 + 4116841 = 4033^2 + 2029^2 .

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20381930.

It is not an unprimeable number, because it can be changed into a prime (20381939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16097 + ... + 17316.

Almost surely, 2^20381930 is an apocalyptic number.

20381930 is a deficient number, since it is larger than the sum of its proper divisors (16908094).

20381930 is a wasteful number, since it uses less digits than its factorization.

20381930 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33481.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 20381930 is about 4514.6350904586. The cubic root of 20381930 is about 273.1587407065.

The spelling of 20381930 in words is "twenty million, three hundred eighty-one thousand, nine hundred thirty".