51397609 has 2 divisors, whose sum is σ = 51397610. Its totient is φ = 51397608.

The previous prime is 51397607. The next prime is 51397631. The reversal of 51397609 is 90679315.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 46199209 + 5198400 = 6797^2 + 2280^2 .

It is a cyclic number.

It is not a de Polignac number, because 51397609 - 2¹ = 51397607 is a prime.

It is a super-3 number, since 3×51397609³ (a number of 24 digits) contains 333 as substring.

Together with 51397607, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (51397601) 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, 25698804 + 25698805.

It is an arithmetic number, because the mean of its divisors is an integer number (25698805).

Almost surely, 2^51397609 is an apocalyptic number.

It is an amenable number.

51397609 is a deficient number, since it is larger than the sum of its proper divisors (1).

51397609 is an equidigital number, since it uses as much as digits as its factorization.

51397609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 51030, while the sum is 40.

The square root of 51397609 is about 7169.2125787983. The cubic root of 51397609 is about 371.8042120186.

The spelling of 51397609 in words is "fifty-one million, three hundred ninety-seven thousand, six hundred nine".