20172389 has 4 divisors (see below), whose sum is σ = 20361024. Its totient is φ = 19983756.

The previous prime is 20172379. The next prime is 20172401. The reversal of 20172389 is 98327102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20172389 - 2²⁰ = 19123813 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 (20172329) 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, 94157 + ... + 94370.

It is an arithmetic number, because the mean of its divisors is an integer number (5090256).

Almost surely, 2^20172389 is an apocalyptic number.

It is an amenable number.

20172389 is a deficient number, since it is larger than the sum of its proper divisors (188635).

20172389 is a wasteful number, since it uses less digits than its factorization.

20172389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188634.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 20172389 is about 4491.3682770399. The cubic root of 20172389 is about 272.2194244765.

The spelling of 20172389 in words is "twenty million, one hundred seventy-two thousand, three hundred eighty-nine".