20575987 has 4 divisors (see below), whose sum is σ = 20668480. Its totient is φ = 20483496.

The previous prime is 20575981. The next prime is 20575991. The reversal of 20575987 is 78957502.

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

It is a cyclic number.

It is not a de Polignac number, because 20575987 - 2⁷ = 20575859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20575981) 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 3 ways as a sum of consecutive naturals, for example, 45912 + ... + 46357.

It is an arithmetic number, because the mean of its divisors is an integer number (5167120).

Almost surely, 2^20575987 is an apocalyptic number.

20575987 is a deficient number, since it is larger than the sum of its proper divisors (92493).

20575987 is an equidigital number, since it uses as much as digits as its factorization.

20575987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92492.

The product of its (nonzero) digits is 176400, while the sum is 43.

The square root of 20575987 is about 4536.0761677908. The cubic root of 20575987 is about 274.0229215200.

The spelling of 20575987 in words is "twenty million, five hundred seventy-five thousand, nine hundred eighty-seven".