20321530 has 8 divisors (see below), whose sum is σ = 36578772. Its totient is φ = 8128608.

The previous prime is 20321447. The next prime is 20321537. The reversal of 20321530 is 3512302.

It can be written as a sum of positive squares in 2 ways, for example, as 20277009 + 44521 = 4503^2 + 211^2 .

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

It is not an unprimeable number, because it can be changed into a prime (20321537) 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 3 ways as a sum of consecutive naturals, for example, 1016067 + ... + 1016086.

Almost surely, 2^20321530 is an apocalyptic number.

20321530 is a deficient number, since it is larger than the sum of its proper divisors (16257242).

20321530 is a wasteful number, since it uses less digits than its factorization.

20321530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2032160.

The product of its (nonzero) digits is 180, while the sum is 16.

The square root of 20321530 is about 4507.9407715719. The cubic root of 20321530 is about 272.8886466840. Note that the first 3 decimals are identical.

Adding to 20321530 its reverse (3512302), we get a palindrome (23833832).

The spelling of 20321530 in words is "twenty million, three hundred twenty-one thousand, five hundred thirty".