20012557 has 4 divisors (see below), whose sum is σ = 20294496. Its totient is φ = 19730620.

The previous prime is 20012543. The next prime is 20012561. The reversal of 20012557 is 75521002.

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 a de Polignac number, because none of the positive numbers 2^k-20012557 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 (20012857) 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, 140863 + ... + 141004.

It is an arithmetic number, because the mean of its divisors is an integer number (5073624).

Almost surely, 2^20012557 is an apocalyptic number.

It is an amenable number.

20012557 is a deficient number, since it is larger than the sum of its proper divisors (281939).

20012557 is an equidigital number, since it uses as much as digits as its factorization.

20012557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281938.

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

The square root of 20012557 is about 4473.5396499864. The cubic root of 20012557 is about 271.4985580113.

Adding to 20012557 its reverse (75521002), we get a palindrome (95533559).

The spelling of 20012557 in words is "twenty million, twelve thousand, five hundred fifty-seven".