51317121361 has 24 divisors (see below), whose sum is σ = 59708658240. Its totient is φ = 43995594720.

The previous prime is 51317121353. The next prime is 51317121367. The reversal of 51317121361 is 16312171315.

It is not a de Polignac number, because 51317121361 - 2³ = 51317121353 is a prime.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (51317121367) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19165 + ... + 320938.

It is an arithmetic number, because the mean of its divisors is an integer number (2487860760).

Almost surely, 2^51317121361 is an apocalyptic number.

It is an amenable number.

51317121361 is a deficient number, since it is larger than the sum of its proper divisors (8391536879).

51317121361 is a wasteful number, since it uses less digits than its factorization.

51317121361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340197 (or 340186 counting only the distinct ones).

The product of its digits is 3780, while the sum is 31.

Adding to 51317121361 its reverse (16312171315), we get a palindrome (67629292676).

The spelling of 51317121361 in words is "fifty-one billion, three hundred seventeen million, one hundred twenty-one thousand, three hundred sixty-one".