20399289 has 8 divisors (see below), whose sum is σ = 27605280. Its totient is φ = 13396416.

The previous prime is 20399279. The next prime is 20399299. The reversal of 20399289 is 98299302.

It is an interprime number because it is at equal distance from previous prime (20399279) and next prime (20399299).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20399289 - 2⁵ = 20399257 is a prime.

It is a super-2 number, since 2×20399289² = 832261983411042, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20399289.

It is not an unprimeable number, because it can be changed into a prime (20399279) 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, 50544 + ... + 50945.

It is an arithmetic number, because the mean of its divisors is an integer number (3450660).

Almost surely, 2^20399289 is an apocalyptic number.

It is an amenable number.

20399289 is a deficient number, since it is larger than the sum of its proper divisors (7205991).

20399289 is a wasteful number, since it uses less digits than its factorization.

20399289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101559.

The product of its (nonzero) digits is 69984, while the sum is 42.

The square root of 20399289 is about 4516.5572065457. The cubic root of 20399289 is about 273.2362671732.

The spelling of 20399289 in words is "twenty million, three hundred ninety-nine thousand, two hundred eighty-nine".