51210331004561 has 4 divisors (see below), whose sum is σ = 54222703416612. Its totient is φ = 48197958592512.

The previous prime is 51210331004557. The next prime is 51210331004617. The reversal of 51210331004561 is 16540013301215.

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 33506222863936 + 17704108140625 = 5788456^2 + 4207625^2 .

It is a cyclic number.

It is not a de Polignac number, because 51210331004561 - 2² = 51210331004557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51210331004761) 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, 1506186206000 + ... + 1506186206033.

It is an arithmetic number, because the mean of its divisors is an integer number (13555675854153).

Almost surely, 2^{51210331004561} is an apocalyptic number.

It is an amenable number.

51210331004561 is a deficient number, since it is larger than the sum of its proper divisors (3012372412051).

51210331004561 is a wasteful number, since it uses less digits than its factorization.

51210331004561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3012372412050.

The product of its (nonzero) digits is 10800, while the sum is 32.

Adding to 51210331004561 its reverse (16540013301215), we get a palindrome (67750344305776).

The spelling of 51210331004561 in words is "fifty-one trillion, two hundred ten billion, three hundred thirty-one million, four thousand, five hundred sixty-one".