20561585 has 16 divisors (see below), whose sum is σ = 28501632. Its totient is φ = 14073600.

The previous prime is 20561579. The next prime is 20561599. The reversal of 20561585 is 58516502.

It is not a de Polignac number, because 20561585 - 2⁶ = 20561521 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10061 + ... + 11930.

It is an arithmetic number, because the mean of its divisors is an integer number (1781352).

Almost surely, 2^20561585 is an apocalyptic number.

It is an amenable number.

20561585 is a deficient number, since it is larger than the sum of its proper divisors (7940047).

20561585 is a wasteful number, since it uses less digits than its factorization.

20561585 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22024.

The product of its (nonzero) digits is 12000, while the sum is 32.

The square root of 20561585 is about 4534.4883945160. The cubic root of 20561585 is about 273.9589732026.

The spelling of 20561585 in words is "twenty million, five hundred sixty-one thousand, five hundred eighty-five".