20004251 has 4 divisors (see below), whose sum is σ = 20021400. Its totient is φ = 19987104.

The previous prime is 20004239. The next prime is 20004253. The reversal of 20004251 is 15240002.

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 20004251 - 2¹⁰ = 20003227 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20004253) 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, 6686 + ... + 9203.

It is an arithmetic number, because the mean of its divisors is an integer number (5005350).

Almost surely, 2^20004251 is an apocalyptic number.

20004251 is a deficient number, since it is larger than the sum of its proper divisors (17149).

20004251 is a wasteful number, since it uses less digits than its factorization.

20004251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17148.

The product of its (nonzero) digits is 80, while the sum is 14.

The square root of 20004251 is about 4472.6112059959. The cubic root of 20004251 is about 271.4609919459.

Adding to 20004251 its reverse (15240002), we get a palindrome (35244253).

The spelling of 20004251 in words is "twenty million, four thousand, two hundred fifty-one".