20538664 has 8 divisors (see below), whose sum is σ = 38510010. Its totient is φ = 10269328.

The previous prime is 20538643. The next prime is 20538673. The reversal of 20538664 is 46683502.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 19802500 + 736164 = 4450^2 + 858^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 1283659 + ... + 1283674.

Almost surely, 2^20538664 is an apocalyptic number.

It is an amenable number.

20538664 is a deficient number, since it is larger than the sum of its proper divisors (17971346).

20538664 is a wasteful number, since it uses less digits than its factorization.

20538664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2567339 (or 2567335 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 34.

The square root of 20538664 is about 4531.9602822620. The cubic root of 20538664 is about 273.8571368835.

The spelling of 20538664 in words is "twenty million, five hundred thirty-eight thousand, six hundred sixty-four".