20561359 has 8 divisors (see below), whose sum is σ = 25306400. Its totient is φ = 16268256.

The previous prime is 20561351. The next prime is 20561369. The reversal of 20561359 is 95316502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20561359 - 2³ = 20561351 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20561359.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20561351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 112884 + ... + 113065.

It is an arithmetic number, because the mean of its divisors is an integer number (3163300).

Almost surely, 2^20561359 is an apocalyptic number.

20561359 is a deficient number, since it is larger than the sum of its proper divisors (4745041).

20561359 is a wasteful number, since it uses less digits than its factorization.

20561359 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 225969.

The product of its (nonzero) digits is 8100, while the sum is 31.

The square root of 20561359 is about 4534.4634743264. The cubic root of 20561359 is about 273.9579694707.

The spelling of 20561359 in words is "twenty million, five hundred sixty-one thousand, three hundred fifty-nine".