20819530 has 16 divisors (see below), whose sum is σ = 38488680. Its totient is φ = 8102592.

The previous prime is 20819521. The next prime is 20819563. The reversal of 20819530 is 3591802.

It can be written as a sum of positive squares in 4 ways, for example, as 20548089 + 271441 = 4533^2 + 521^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27765 + ... + 28504.

Almost surely, 2^20819530 is an apocalyptic number.

20819530 is a deficient number, since it is larger than the sum of its proper divisors (17669150).

20819530 is a wasteful number, since it uses less digits than its factorization.

20819530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56313.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 20819530 is about 4562.8423159255. The cubic root of 20819530 is about 275.0998205117.

It can be divided in two parts, 2081 and 9530, that added together give a palindrome (11611).

The spelling of 20819530 in words is "twenty million, eight hundred nineteen thousand, five hundred thirty".