51091393 has 2 divisors, whose sum is σ = 51091394. Its totient is φ = 51091392.

The previous prime is 51091357. The next prime is 51091423. The reversal of 51091393 is 39319015.

51091393 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 40806544 + 10284849 = 6388^2 + 3207^2 .

It is a cyclic number.

It is not a de Polignac number, because 51091393 - 2²¹ = 48994241 is a prime.

It is a super-2 number, since 2×51091393² = 5220660877360898, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (51091333) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25545696 + 25545697.

It is an arithmetic number, because the mean of its divisors is an integer number (25545697).

Almost surely, 2^51091393 is an apocalyptic number.

It is an amenable number.

51091393 is a deficient number, since it is larger than the sum of its proper divisors (1).

51091393 is an equidigital number, since it uses as much as digits as its factorization.

51091393 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3645, while the sum is 31.

The square root of 51091393 is about 7147.8243543053. The cubic root of 51091393 is about 371.0643640313.

The spelling of 51091393 in words is "fifty-one million, ninety-one thousand, three hundred ninety-three".