51212251 has 4 divisors (see below), whose sum is σ = 51304752. Its totient is φ = 51119752.

The previous prime is 51212221. The next prime is 51212261. The reversal of 51212251 is 15221215.

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 51212251 - 2⁵ = 51212219 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51212221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45415 + ... + 46528.

It is an arithmetic number, because the mean of its divisors is an integer number (12826188).

Almost surely, 2^51212251 is an apocalyptic number.

51212251 is a deficient number, since it is larger than the sum of its proper divisors (92501).

51212251 is an equidigital number, since it uses as much as digits as its factorization.

51212251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92500.

The product of its digits is 200, while the sum is 19.

The square root of 51212251 is about 7156.2735414460. The cubic root of 51212251 is about 371.3567210484.

Adding to 51212251 its reverse (15221215), we get a palindrome (66433466).

The spelling of 51212251 in words is "fifty-one million, two hundred twelve thousand, two hundred fifty-one".