51111313243261 has 4 divisors (see below), whose sum is σ = 51132998147292. Its totient is φ = 51089628339232.

The previous prime is 51111313243241. The next prime is 51111313243307. The reversal of 51111313243261 is 16234231311115.

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 19736863579161 + 31374449664100 = 4442619^2 + 5601290^2 .

It is a cyclic number.

It is not a de Polignac number, because 51111313243261 - 2¹⁵ = 51111313210493 is a prime.

It is a super-2 number, since 2×51111313243261² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51111313243231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10842448480 + ... + 10842453193.

It is an arithmetic number, because the mean of its divisors is an integer number (12783249536823).

Almost surely, 2^{51111313243261} is an apocalyptic number.

It is an amenable number.

51111313243261 is a deficient number, since it is larger than the sum of its proper divisors (21684904031).

51111313243261 is a wasteful number, since it uses less digits than its factorization.

51111313243261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21684904030.

The product of its digits is 12960, while the sum is 34.

Adding to 51111313243261 its reverse (16234231311115), we get a palindrome (67345544554376).

The spelling of 51111313243261 in words is "fifty-one trillion, one hundred eleven billion, three hundred thirteen million, two hundred forty-three thousand, two hundred sixty-one".