51216317 has 2 divisors, whose sum is σ = 51216318. Its totient is φ = 51216316.

The previous prime is 51216313. The next prime is 51216353. The reversal of 51216317 is 71361215.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 33860761 + 17355556 = 5819^2 + 4166^2 .

It is a cyclic number.

It is not a de Polignac number, because 51216317 - 2² = 51216313 is a prime.

It is a super-2 number, since 2×51216317² = 5246222254088978, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51216313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25608158 + 25608159.

It is an arithmetic number, because the mean of its divisors is an integer number (25608159).

Almost surely, 2^51216317 is an apocalyptic number.

It is an amenable number.

51216317 is a deficient number, since it is larger than the sum of its proper divisors (1).

51216317 is an equidigital number, since it uses as much as digits as its factorization.

51216317 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1260, while the sum is 26.

The square root of 51216317 is about 7156.5576222092. The cubic root of 51216317 is about 371.3665487520.

The spelling of 51216317 in words is "fifty-one million, two hundred sixteen thousand, three hundred seventeen".