51698813 has 2 divisors, whose sum is σ = 51698814. Its totient is φ = 51698812.

The previous prime is 51698789. The next prime is 51698821. The reversal of 51698813 is 31889615.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 45657049 + 6041764 = 6757^2 + 2458^2 .

It is a cyclic number.

It is not a de Polignac number, because 51698813 - 2⁶ = 51698749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51698113) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25849406 + 25849407.

It is an arithmetic number, because the mean of its divisors is an integer number (25849407).

Almost surely, 2^51698813 is an apocalyptic number.

It is an amenable number.

51698813 is a deficient number, since it is larger than the sum of its proper divisors (1).

51698813 is an equidigital number, since it uses as much as digits as its factorization.

51698813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51840, while the sum is 41.

The square root of 51698813 is about 7190.1886623370. The cubic root of 51698813 is about 372.5290892107.

The spelling of 51698813 in words is "fifty-one million, six hundred ninety-eight thousand, eight hundred thirteen".