20055139 has 4 divisors (see below), whose sum is σ = 21597856. Its totient is φ = 18512424.

The previous prime is 20055137. The next prime is 20055143. The reversal of 20055139 is 93155002.

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 20055139 - 2¹ = 20055137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20055131) 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, 771339 + ... + 771364.

It is an arithmetic number, because the mean of its divisors is an integer number (5399464).

Almost surely, 2^20055139 is an apocalyptic number.

20055139 is a deficient number, since it is larger than the sum of its proper divisors (1542717).

20055139 is a wasteful number, since it uses less digits than its factorization.

20055139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1542716.

The product of its (nonzero) digits is 1350, while the sum is 25.

The square root of 20055139 is about 4478.2964394957. The cubic root of 20055139 is about 271.6909832241.

The spelling of 20055139 in words is "twenty million, fifty-five thousand, one hundred thirty-nine".