51504251 has 4 divisors (see below), whose sum is σ = 51820392. Its totient is φ = 51188112.

The previous prime is 51504247. The next prime is 51504253. The reversal of 51504251 is 15240515.

It is a happy number.

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 51504251 - 2² = 51504247 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51504253) 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, 157826 + ... + 158151.

It is an arithmetic number, because the mean of its divisors is an integer number (12955098).

Almost surely, 2^51504251 is an apocalyptic number.

51504251 is a deficient number, since it is larger than the sum of its proper divisors (316141).

51504251 is a wasteful number, since it uses less digits than its factorization.

51504251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 316140.

The product of its (nonzero) digits is 1000, while the sum is 23.

The square root of 51504251 is about 7176.6462222963. The cubic root of 51504251 is about 372.0611795743.

Adding to 51504251 its reverse (15240515), we get a palindrome (66744766).

The spelling of 51504251 in words is "fifty-one million, five hundred four thousand, two hundred fifty-one".