20556587 has 8 divisors (see below), whose sum is σ = 21845376. Its totient is φ = 19276672.

The previous prime is 20556551. The next prime is 20556607. The reversal of 20556587 is 78565502.

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 20556587 - 2¹² = 20552491 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20556587.

It is not an unprimeable number, because it can be changed into a prime (20556517) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2918 + ... + 7044.

It is an arithmetic number, because the mean of its divisors is an integer number (2730672).

Almost surely, 2^20556587 is an apocalyptic number.

20556587 is a deficient number, since it is larger than the sum of its proper divisors (1288789).

20556587 is a wasteful number, since it uses less digits than its factorization.

20556587 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4437.

The product of its (nonzero) digits is 84000, while the sum is 38.

The square root of 20556587 is about 4533.9372514405. The cubic root of 20556587 is about 273.9367739103.

The spelling of 20556587 in words is "twenty million, five hundred fifty-six thousand, five hundred eighty-seven".