20353987 has 4 divisors (see below), whose sum is σ = 20377336. Its totient is φ = 20330640.

The previous prime is 20353967. The next prime is 20354023. The reversal of 20353987 is 78935302.

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 20353987 - 2¹⁹ = 19829699 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20353937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10314 + ... + 12127.

It is an arithmetic number, because the mean of its divisors is an integer number (5094334).

Almost surely, 2^20353987 is an apocalyptic number.

20353987 is a deficient number, since it is larger than the sum of its proper divisors (23349).

20353987 is an equidigital number, since it uses as much as digits as its factorization.

20353987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23348.

The product of its (nonzero) digits is 45360, while the sum is 37.

The square root of 20353987 is about 4511.5393160206. The cubic root of 20353987 is about 273.0338528688.

The spelling of 20353987 in words is "twenty million, three hundred fifty-three thousand, nine hundred eighty-seven".