51165082809 has 45 divisors (see below), whose sum is σ = 78469456989. Its totient is φ = 33223815360.

The previous prime is 51165082763. The next prime is 51165082811. The reversal of 51165082809 is 90828056115.

It is a happy number.

The square root of 51165082809 is 226197.

It is a perfect power (a square), and thus also a powerful number.

51165082809 is a `hidden beast` number, since 5 + 116 + 508 + 28 + 0 + 9 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 47299725225 + 3865357584 = 217485^2 + 62172^2 .

It is not a de Polignac number, because 51165082809 - 2¹³ = 51165074617 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51165082889) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 83466387 + ... + 83466999.

Almost surely, 2^51165082809 is an apocalyptic number.

51165082809 is the 226197-th square number.

51165082809 is the 113099-th centered octagonal number.

It is an amenable number.

51165082809 is a deficient number, since it is larger than the sum of its proper divisors (27304374180).

51165082809 is an frugal number, since it uses more digits than its factorization.

51165082809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1320 (or 657 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 45.

The spelling of 51165082809 in words is "fifty-one billion, one hundred sixty-five million, eighty-two thousand, eight hundred nine".