20172489 has 24 divisors (see below), whose sum is σ = 29177280. Its totient is φ = 12390144.

The previous prime is 20172469. The next prime is 20172491. The reversal of 20172489 is 98427102.

It is a happy number.

It is not a de Polignac number, because 20172489 - 2⁵ = 20172457 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20172409) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 45732 + ... + 46170.

It is an arithmetic number, because the mean of its divisors is an integer number (1215720).

Almost surely, 2^20172489 is an apocalyptic number.

It is an amenable number.

20172489 is a deficient number, since it is larger than the sum of its proper divisors (9004791).

20172489 is a wasteful number, since it uses less digits than its factorization.

20172489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 529 (or 512 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 20172489 is about 4491.3794094910. The cubic root of 20172489 is about 272.2198742975.

Subtracting from 20172489 its product of nonzero digits (8064), we obtain a triangular number (20164425 = T₆₃₅₀).

The spelling of 20172489 in words is "twenty million, one hundred seventy-two thousand, four hundred eighty-nine".