51021225251 has 2 divisors, whose sum is σ = 51021225252. Its totient is φ = 51021225250.

The previous prime is 51021225247. The next prime is 51021225263. The reversal of 51021225251 is 15252212015.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51021225251 - 2² = 51021225247 is a prime.

It is a super-2 number, since 2×51021225251² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 51021225251.

It is not a weakly prime, because it can be changed into another prime (51021225551) 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 as a sum of consecutive naturals, namely, 25510612625 + 25510612626.

It is an arithmetic number, because the mean of its divisors is an integer number (25510612626).

Almost surely, 2^51021225251 is an apocalyptic number.

51021225251 is a deficient number, since it is larger than the sum of its proper divisors (1).

51021225251 is an equidigital number, since it uses as much as digits as its factorization.

51021225251 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2000, while the sum is 26.

Adding to 51021225251 its reverse (15252212015), we get a palindrome (66273437266).

The spelling of 51021225251 in words is "fifty-one billion, twenty-one million, two hundred twenty-five thousand, two hundred fifty-one".