20581139 has 8 divisors (see below), whose sum is σ = 21654528. Its totient is φ = 19535040.

The previous prime is 20581103. The next prime is 20581153. The reversal of 20581139 is 93118502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20581139 - 2²⁴ = 3803923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20581189) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5267 + ... + 8300.

It is an arithmetic number, because the mean of its divisors is an integer number (2706816).

Almost surely, 2^20581139 is an apocalyptic number.

20581139 is a deficient number, since it is larger than the sum of its proper divisors (1073389).

20581139 is a wasteful number, since it uses less digits than its factorization.

20581139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13645.

The product of its (nonzero) digits is 2160, while the sum is 29.

The square root of 20581139 is about 4536.6440239455. The cubic root of 20581139 is about 274.0457903829.

The spelling of 20581139 in words is "twenty million, five hundred eighty-one thousand, one hundred thirty-nine".