20015869 has 4 divisors (see below), whose sum is σ = 20344060. Its totient is φ = 19687680.

The previous prime is 20015839. The next prime is 20015893. The reversal of 20015869 is 96851002.

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

It can be written as a sum of positive squares in 2 ways, for example, as 980100 + 19035769 = 990^2 + 4363^2 .

It is a cyclic number.

It is not a de Polignac number, because 20015869 - 2⁹ = 20015357 is a prime.

It is a super-2 number, since 2×20015869² = 801270023650322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20015869.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20015839) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 164004 + ... + 164125.

It is an arithmetic number, because the mean of its divisors is an integer number (5086015).

Almost surely, 2^20015869 is an apocalyptic number.

It is an amenable number.

20015869 is a deficient number, since it is larger than the sum of its proper divisors (328191).

20015869 is an equidigital number, since it uses as much as digits as its factorization.

20015869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328190.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 20015869 is about 4473.9098113395. The cubic root of 20015869 is about 271.5135345020.

The spelling of 20015869 in words is "twenty million, fifteen thousand, eight hundred sixty-nine".