51215084617 has 4 divisors (see below), whose sum is σ = 51215937220. Its totient is φ = 51214232016.

The previous prime is 51215084587. The next prime is 51215084671. The reversal of 51215084617 is 71648051215.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 25654749241 + 25560335376 = 160171^2 + 159876^2 .

It is a cyclic number.

It is not a de Polignac number, because 51215084617 - 2¹⁹ = 51214560329 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51215084617.

It is not an unprimeable number, because it can be changed into a prime (51215084917) 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, 328758 + ... + 458815.

It is an arithmetic number, because the mean of its divisors is an integer number (12803984305).

Almost surely, 2^51215084617 is an apocalyptic number.

It is an amenable number.

51215084617 is a deficient number, since it is larger than the sum of its proper divisors (852603).

51215084617 is an equidigital number, since it uses as much as digits as its factorization.

51215084617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 852602.

The product of its (nonzero) digits is 67200, while the sum is 40.

The spelling of 51215084617 in words is "fifty-one billion, two hundred fifteen million, eighty-four thousand, six hundred seventeen".