20664530 has 16 divisors (see below), whose sum is σ = 38479320. Its totient is φ = 7980672.

The previous prime is 20664529. The next prime is 20664587. The reversal of 20664530 is 3546602.

It can be written as a sum of positive squares in 4 ways, for example, as 19193161 + 1471369 = 4381^2 + 1213^2 .

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20664530.

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, 35339 + ... + 35918.

Almost surely, 2^20664530 is an apocalyptic number.

20664530 is a deficient number, since it is larger than the sum of its proper divisors (17814790).

20664530 is a wasteful number, since it uses less digits than its factorization.

20664530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71293.

The product of its (nonzero) digits is 4320, while the sum is 26.

The square root of 20664530 is about 4545.8255575858. The cubic root of 20664530 is about 274.4154193666.

The spelling of 20664530 in words is "twenty million, six hundred sixty-four thousand, five hundred thirty".