51398609 has 2 divisors, whose sum is σ = 51398610. Its totient is φ = 51398608.

The previous prime is 51398603. The next prime is 51398687. The reversal of 51398609 is 90689315.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49843600 + 1555009 = 7060^2 + 1247^2 .

It is a cyclic number.

It is not a de Polignac number, because 51398609 - 2²⁴ = 34621393 is a prime.

It is not a weakly prime, because it can be changed into another prime (51398603) 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, 25699304 + 25699305.

It is an arithmetic number, because the mean of its divisors is an integer number (25699305).

Almost surely, 2^51398609 is an apocalyptic number.

It is an amenable number.

51398609 is a deficient number, since it is larger than the sum of its proper divisors (1).

51398609 is an equidigital number, since it uses as much as digits as its factorization.

51398609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 58320, while the sum is 41.

The square root of 51398609 is about 7169.2823211253. The cubic root of 51398609 is about 371.8066232968.

The spelling of 51398609 in words is "fifty-one million, three hundred ninety-eight thousand, six hundred nine".