51218969 has 2 divisors, whose sum is σ = 51218970. Its totient is φ = 51218968.

The previous prime is 51218941. The next prime is 51218971. The reversal of 51218969 is 96981215.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31753225 + 19465744 = 5635^2 + 4412^2 .

It is a cyclic number.

It is not a de Polignac number, because 51218969 - 2¹² = 51214873 is a prime.

It is a super-2 number, since 2×51218969² = 5246765570845922, which contains 22 as substring.

Together with 51218971, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_3069779 and since 51218969 and 3069779 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (51218929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25609484 + 25609485.

It is an arithmetic number, because the mean of its divisors is an integer number (25609485).

Almost surely, 2^51218969 is an apocalyptic number.

It is an amenable number.

51218969 is a deficient number, since it is larger than the sum of its proper divisors (1).

51218969 is an equidigital number, since it uses as much as digits as its factorization.

51218969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 38880, while the sum is 41.

The square root of 51218969 is about 7156.7429044224. The cubic root of 51218969 is about 371.3729584742.

The spelling of 51218969 in words is "fifty-one million, two hundred eighteen thousand, nine hundred sixty-nine".