20287899 has 6 divisors (see below), whose sum is σ = 29304756. Its totient is φ = 13525260.

The previous prime is 20287889. The next prime is 20287901. The reversal of 20287899 is 99878202.

It is not a de Polignac number, because 20287899 - 2²³ = 11899291 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20287819) 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 5 ways as a sum of consecutive naturals, for example, 1127097 + ... + 1127114.

It is an arithmetic number, because the mean of its divisors is an integer number (4884126).

Almost surely, 2^20287899 is an apocalyptic number.

20287899 is a deficient number, since it is larger than the sum of its proper divisors (9016857).

20287899 is a wasteful number, since it uses less digits than its factorization.

20287899 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2254217 (or 2254214 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 20287899 is about 4504.2090315615. The cubic root of 20287899 is about 272.7380250609.

The spelling of 20287899 in words is "twenty million, two hundred eighty-seven thousand, eight hundred ninety-nine".