20120557 has 4 divisors (see below), whose sum is σ = 20244160. Its totient is φ = 19996956.

The previous prime is 20120543. The next prime is 20120623. The reversal of 20120557 is 75502102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20120557 - 2¹¹ = 20118509 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 (20120257) 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, 61557 + ... + 61882.

It is an arithmetic number, because the mean of its divisors is an integer number (5061040).

Almost surely, 2^20120557 is an apocalyptic number.

It is an amenable number.

20120557 is a deficient number, since it is larger than the sum of its proper divisors (123603).

20120557 is a wasteful number, since it uses less digits than its factorization.

20120557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123602.

The product of its (nonzero) digits is 700, while the sum is 22.

The square root of 20120557 is about 4485.5943864777. The cubic root of 20120557 is about 271.9860728524.

Adding to 20120557 its reverse (75502102), we get a palindrome (95622659).

The spelling of 20120557 in words is "twenty million, one hundred twenty thousand, five hundred fifty-seven".