20003257 has 4 divisors (see below), whose sum is σ = 21056080. Its totient is φ = 18950436.

The previous prime is 20003231. The next prime is 20003267. The reversal of 20003257 is 75230002.

It is a happy number.

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-20003257 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19), and also a Moran number because the ratio is a prime number: 1052803 = 20003257 / (2 + 0 + 0 + 0 + 3 + 2 + 5 + 7).

It is the 4473-rd Hogben number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20003227) by changing a digit.

It is a nontrivial repunit in base 4472.

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, 526383 + ... + 526420.

It is an arithmetic number, because the mean of its divisors is an integer number (5264020).

Almost surely, 2^20003257 is an apocalyptic number.

It is an amenable number.

20003257 is a deficient number, since it is larger than the sum of its proper divisors (1052823).

20003257 is a wasteful number, since it uses less digits than its factorization.

20003257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1052822.

The product of its (nonzero) digits is 420, while the sum is 19.

The square root of 20003257 is about 4472.5000838457. The cubic root of 20003257 is about 271.4564956233.

Adding to 20003257 its reverse (75230002), we get a palindrome (95233259).

The spelling of 20003257 in words is "twenty million, three thousand, two hundred fifty-seven".