20566987 has 16 divisors (see below), whose sum is σ = 25171200. Its totient is φ = 16411680.

The previous prime is 20566979. The next prime is 20566999. The reversal of 20566987 is 78966502.

It is a cyclic number.

It is not a de Polignac number, because 20566987 - 2³ = 20566979 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20566967) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6537 + ... + 9157.

It is an arithmetic number, because the mean of its divisors is an integer number (1573200).

Almost surely, 2^20566987 is an apocalyptic number.

20566987 is a deficient number, since it is larger than the sum of its proper divisors (4604213).

20566987 is a wasteful number, since it uses less digits than its factorization.

20566987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2706.

The product of its (nonzero) digits is 181440, while the sum is 43.

The square root of 20566987 is about 4535.0840124523. The cubic root of 20566987 is about 273.9829628705.

The spelling of 20566987 in words is "twenty million, five hundred sixty-six thousand, nine hundred eighty-seven".