20081539 has 4 divisors (see below), whose sum is σ = 21262824. Its totient is φ = 18900256.

The previous prime is 20081531. The next prime is 20081561. The reversal of 20081539 is 93518002.

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 20081539 - 2³ = 20081531 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20081531) 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, 590617 + ... + 590650.

It is an arithmetic number, because the mean of its divisors is an integer number (5315706).

Almost surely, 2^20081539 is an apocalyptic number.

20081539 is a deficient number, since it is larger than the sum of its proper divisors (1181285).

20081539 is a wasteful number, since it uses less digits than its factorization.

20081539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1181284.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 20081539 is about 4481.2430195204. The cubic root of 20081539 is about 271.8101463136.

The spelling of 20081539 in words is "twenty million, eighty-one thousand, five hundred thirty-nine".