51115121 has 2 divisors, whose sum is σ = 51115122. Its totient is φ = 51115120.

The previous prime is 51115117. The next prime is 51115123. The reversal of 51115121 is 12151115.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41280625 + 9834496 = 6425^2 + 3136^2 .

It is a cyclic number.

It is not a de Polignac number, because 51115121 - 2² = 51115117 is a prime.

It is a super-2 number, since 2×51115121² = 5225511189689282, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 51115123, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 51115121.

It is not a weakly prime, because it can be changed into another prime (51115123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25557560 + 25557561.

It is an arithmetic number, because the mean of its divisors is an integer number (25557561).

Almost surely, 2^51115121 is an apocalyptic number.

It is an amenable number.

51115121 is a deficient number, since it is larger than the sum of its proper divisors (1).

51115121 is an equidigital number, since it uses as much as digits as its factorization.

51115121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 50, while the sum is 17.

The square root of 51115121 is about 7149.4839673923. The cubic root of 51115121 is about 371.1217987056.

Adding to 51115121 its reverse (12151115), we get a palindrome (63266236).

The spelling of 51115121 in words is "fifty-one million, one hundred fifteen thousand, one hundred twenty-one".