20538247 has 4 divisors (see below), whose sum is σ = 20844856. Its totient is φ = 20231640.

The previous prime is 20538239. The next prime is 20538283. The reversal of 20538247 is 74283502.

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 20538247 - 2³ = 20538239 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 (20530247) 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 3 ways as a sum of consecutive naturals, for example, 153204 + ... + 153337.

It is an arithmetic number, because the mean of its divisors is an integer number (5211214).

Almost surely, 2^20538247 is an apocalyptic number.

20538247 is a deficient number, since it is larger than the sum of its proper divisors (306609).

20538247 is an equidigital number, since it uses as much as digits as its factorization.

20538247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 306608.

The product of its (nonzero) digits is 13440, while the sum is 31.

The square root of 20538247 is about 4531.9142754470. The cubic root of 20538247 is about 273.8552834816.

The spelling of 20538247 in words is "twenty million, five hundred thirty-eight thousand, two hundred forty-seven".