20165899 has 8 divisors (see below), whose sum is σ = 21863072. Its totient is φ = 18489600.

The previous prime is 20165881. The next prime is 20165911. The reversal of 20165899 is 99856102.

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 20165899 - 2¹³ = 20157707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20165819) 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 7 ways as a sum of consecutive naturals, for example, 3174 + ... + 7099.

It is an arithmetic number, because the mean of its divisors is an integer number (2732884).

Almost surely, 2^20165899 is an apocalyptic number.

20165899 is a deficient number, since it is larger than the sum of its proper divisors (1697173).

20165899 is a wasteful number, since it uses less digits than its factorization.

20165899 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10437.

The product of its (nonzero) digits is 38880, while the sum is 40.

The square root of 20165899 is about 4490.6457219424. The cubic root of 20165899 is about 272.1902279088.

The spelling of 20165899 in words is "twenty million, one hundred sixty-five thousand, eight hundred ninety-nine".