20549389 has 16 divisors (see below), whose sum is σ = 24054912. Its totient is φ = 17192448.

The previous prime is 20549381. The next prime is 20549407. The reversal of 20549389 is 98394502.

20549389 = 456² + 457² + ... + 538².

It is a happy number.

It is not a de Polignac number, because 20549389 - 2³ = 20549381 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20549381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 65497 + ... + 65809.

It is an arithmetic number, because the mean of its divisors is an integer number (1503432).

Almost surely, 2^20549389 is an apocalyptic number.

It is an amenable number.

20549389 is a deficient number, since it is larger than the sum of its proper divisors (3505523).

20549389 is a wasteful number, since it uses less digits than its factorization.

20549389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 516.

The product of its (nonzero) digits is 77760, while the sum is 40.

The square root of 20549389 is about 4533.1433906286. The cubic root of 20549389 is about 273.9047966972.

It can be divided in two parts, 205 and 49389, that added together give a palindrome (49594).

The spelling of 20549389 in words is "twenty million, five hundred forty-nine thousand, three hundred eighty-nine".