20664648 has 48 divisors (see below), whose sum is σ = 57486780. Its totient is φ = 6701184.

The previous prime is 20664641. The next prime is 20664653. The reversal of 20664648 is 84646602.

It is a happy number.

20664648 is a `hidden beast` number, since 2 + 0 + 6 + 6 + 4 + 648 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 17489124 + 3175524 = 4182^2 + 1782^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (20664641) 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 11 ways as a sum of consecutive naturals, for example, 1215 + ... + 6542.

Almost surely, 2^20664648 is an apocalyptic number.

It is an amenable number.

20664648 is an abundant number, since it is smaller than the sum of its proper divisors (36822132).

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

20664648 is a wasteful number, since it uses less digits than its factorization.

20664648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7806 (or 7799 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

The square root of 20664648 is about 4545.8385365079. The cubic root of 20664648 is about 274.4159416941.

It can be divided in two parts, 20664 and 648, that added together give a palindrome (21312).

The spelling of 20664648 in words is "twenty million, six hundred sixty-four thousand, six hundred forty-eight".