20320660 has 12 divisors (see below), whose sum is σ = 42673428. Its totient is φ = 8128256.

The previous prime is 20320609. The next prime is 20320669. The reversal of 20320660 is 6602302.

It can be written as a sum of positive squares in 2 ways, for example, as 11641744 + 8678916 = 3412^2 + 2946^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20320669) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 507997 + ... + 508036.

It is an arithmetic number, because the mean of its divisors is an integer number (3556119).

Almost surely, 2^20320660 is an apocalyptic number.

20320660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20320660 is an abundant number, since it is smaller than the sum of its proper divisors (22352768).

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

20320660 is a wasteful number, since it uses less digits than its factorization.

20320660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1016042 (or 1016040 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 19.

The square root of 20320660 is about 4507.8442741514. The cubic root of 20320660 is about 272.8847523494.

Adding to 20320660 its reverse (6602302), we get a palindrome (26922962).

The spelling of 20320660 in words is "twenty million, three hundred twenty thousand, six hundred sixty".