20564629 has 4 divisors (see below), whose sum is σ = 20579020. Its totient is φ = 20550240.

The previous prime is 20564623. The next prime is 20564639. The reversal of 20564629 is 92646502.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18232900 + 2331729 = 4270^2 + 1527^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20564629 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20564594 and 20564603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20564623) 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, 4782 + ... + 7999.

It is an arithmetic number, because the mean of its divisors is an integer number (5144755).

Almost surely, 2^20564629 is an apocalyptic number.

It is an amenable number.

20564629 is a deficient number, since it is larger than the sum of its proper divisors (14391).

20564629 is a wasteful number, since it uses less digits than its factorization.

20564629 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14390.

The product of its (nonzero) digits is 25920, while the sum is 34.

The square root of 20564629 is about 4534.8240318672. The cubic root of 20564629 is about 273.9724917773.

The spelling of 20564629 in words is "twenty million, five hundred sixty-four thousand, six hundred twenty-nine".