20389399 has 4 divisors (see below), whose sum is σ = 20823264. Its totient is φ = 19955536.

The previous prime is 20389387. The next prime is 20389417. The reversal of 20389399 is 99398302.

It is a happy number.

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 20389399 - 2¹⁵ = 20356631 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20389319) 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, 216862 + ... + 216955.

It is an arithmetic number, because the mean of its divisors is an integer number (5205816).

Almost surely, 2^20389399 is an apocalyptic number.

20389399 is a deficient number, since it is larger than the sum of its proper divisors (433865).

20389399 is an equidigital number, since it uses as much as digits as its factorization.

20389399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433864.

The product of its (nonzero) digits is 104976, while the sum is 43.

The square root of 20389399 is about 4515.4622133288. The cubic root of 20389399 is about 273.1921031582.

The spelling of 20389399 in words is "twenty million, three hundred eighty-nine thousand, three hundred ninety-nine".