20127557 has 4 divisors (see below), whose sum is σ = 20255916. Its totient is φ = 19999200.

The previous prime is 20127533. The next prime is 20127571. The reversal of 20127557 is 75572102.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11282881 + 8844676 = 3359^2 + 2974^2 .

It is a cyclic number.

It is not a de Polignac number, because 20127557 - 2⁶ = 20127493 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 (20127257) 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, 63944 + ... + 64257.

It is an arithmetic number, because the mean of its divisors is an integer number (5063979).

Almost surely, 2^20127557 is an apocalyptic number.

It is an amenable number.

20127557 is a deficient number, since it is larger than the sum of its proper divisors (128359).

20127557 is a wasteful number, since it uses less digits than its factorization.

20127557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128358.

The product of its (nonzero) digits is 4900, while the sum is 29.

The square root of 20127557 is about 4486.3745942576. The cubic root of 20127557 is about 272.0176107758.

Adding to 20127557 its reverse (75572102), we get a palindrome (95699659).

The spelling of 20127557 in words is "twenty million, one hundred twenty-seven thousand, five hundred fifty-seven".