20381390 has 8 divisors (see below), whose sum is σ = 36686520. Its totient is φ = 8152552.

The previous prime is 20381369. The next prime is 20381399. The reversal of 20381390 is 9318302.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20381399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1019060 + ... + 1019079.

It is an arithmetic number, because the mean of its divisors is an integer number (4585815).

Almost surely, 2^20381390 is an apocalyptic number.

20381390 is a deficient number, since it is larger than the sum of its proper divisors (16305130).

20381390 is a wasteful number, since it uses less digits than its factorization.

20381390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2038146.

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

The square root of 20381390 is about 4514.5752845644. The cubic root of 20381390 is about 273.1563283241.

Adding to 20381390 its reverse (9318302), we get a palindrome (29699692).

The spelling of 20381390 in words is "twenty million, three hundred eighty-one thousand, three hundred ninety".