20390145 has 16 divisors (see below), whose sum is σ = 33506880. Its totient is φ = 10580544.

The previous prime is 20390129. The next prime is 20390147. The reversal of 20390145 is 54109302.

It is not a de Polignac number, because 20390145 - 2⁴ = 20390129 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20390147) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17815 + ... + 18924.

It is an arithmetic number, because the mean of its divisors is an integer number (2094180).

Almost surely, 2^20390145 is an apocalyptic number.

It is an amenable number.

20390145 is a deficient number, since it is larger than the sum of its proper divisors (13116735).

20390145 is a wasteful number, since it uses less digits than its factorization.

20390145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36784.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 20390145 is about 4515.5448176272. The cubic root of 20390145 is about 273.1954349358.

Adding to 20390145 its reverse (54109302), we get a palindrome (74499447).

The spelling of 20390145 in words is "twenty million, three hundred ninety thousand, one hundred forty-five".