20539871 has 6 divisors (see below), whose sum is σ = 22577016. Its totient is φ = 18672500.

The previous prime is 20539867. The next prime is 20539873. The reversal of 20539871 is 17893502.

It is not a de Polignac number, because 20539871 - 2² = 20539867 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20539873) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 84755 + ... + 84996.

It is an arithmetic number, because the mean of its divisors is an integer number (3762836).

Almost surely, 2^20539871 is an apocalyptic number.

20539871 is a deficient number, since it is larger than the sum of its proper divisors (2037145).

20539871 is a wasteful number, since it uses less digits than its factorization.

20539871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169773 (or 169762 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 20539871 is about 4532.0934456386. The cubic root of 20539871 is about 273.8625013852.

The spelling of 20539871 in words is "twenty million, five hundred thirty-nine thousand, eight hundred seventy-one".