51789509 has 2 divisors, whose sum is σ = 51789510. Its totient is φ = 51789508.

The previous prime is 51789503. The next prime is 51789511. The reversal of 51789509 is 90598715.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51165409 + 624100 = 7153^2 + 790^2 .

It is a cyclic number.

It is not a de Polignac number, because 51789509 - 2²⁰ = 50740933 is a prime.

It is a super-2 number, since 2×51789509² = 5364306484922162, which contains 22 as substring.

Together with 51789511, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51789509.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51789503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25894754 + 25894755.

It is an arithmetic number, because the mean of its divisors is an integer number (25894755).

Almost surely, 2^51789509 is an apocalyptic number.

It is an amenable number.

51789509 is a deficient number, since it is larger than the sum of its proper divisors (1).

51789509 is an equidigital number, since it uses as much as digits as its factorization.

51789509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 113400, while the sum is 44.

The square root of 51789509 is about 7196.4928263704. The cubic root of 51789509 is about 372.7468063943.

The spelling of 51789509 in words is "fifty-one million, seven hundred eighty-nine thousand, five hundred nine".