20718530 has 32 divisors (see below), whose sum is σ = 43666560. Its totient is φ = 6929280.

The previous prime is 20718497. The next prime is 20718539. The reversal of 20718530 is 3581702.

It is a self number, because there is not a number n which added to its sum of digits gives 20718530.

It is not an unprimeable number, because it can be changed into a prime (20718539) 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 15 ways as a sum of consecutive naturals, for example, 740 + ... + 6479.

It is an arithmetic number, because the mean of its divisors is an integer number (1364580).

Almost surely, 2^20718530 is an apocalyptic number.

20718530 is an abundant number, since it is smaller than the sum of its proper divisors (22948030).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20718530 is a wasteful number, since it uses less digits than its factorization.

20718530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7274.

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 20718530 is about 4551.7611976025. The cubic root of 20718530 is about 274.6542431489.

It can be divided in two parts, 2071 and 8530, that added together give a palindrome (10601).

The spelling of 20718530 in words is "twenty million, seven hundred eighteen thousand, five hundred thirty".