51387585509 has 8 divisors (see below), whose sum is σ = 55342909272. Its totient is φ = 47432609280.

The previous prime is 51387585443. The next prime is 51387585521. The reversal of 51387585509 is 90558578315.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 32576640100 + 18810945409 = 180490^2 + 137153^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 51387585509 - 2¹⁶ = 51387519973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51387585559) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 276557 + ... + 423389.

It is an arithmetic number, because the mean of its divisors is an integer number (6917863659).

Almost surely, 2^51387585509 is an apocalyptic number.

It is an amenable number.

51387585509 is a deficient number, since it is larger than the sum of its proper divisors (3955323763).

51387585509 is a wasteful number, since it uses less digits than its factorization.

51387585509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173767.

The product of its (nonzero) digits is 7560000, while the sum is 56.

The spelling of 51387585509 in words is "fifty-one billion, three hundred eighty-seven million, five hundred eighty-five thousand, five hundred nine".