51729985 has 4 divisors (see below), whose sum is σ = 62075988. Its totient is φ = 41383984.

The previous prime is 51729973. The next prime is 51729991. The reversal of 51729985 is 58992715.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 58992715 = 5 ⋅11798543.

It can be written as a sum of positive squares in 2 ways, for example, as 6517809 + 45212176 = 2553^2 + 6724^2 .

It is a cyclic number.

It is not a de Polignac number, because 51729985 - 2⁷ = 51729857 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 5172994 + ... + 5173003.

It is an arithmetic number, because the mean of its divisors is an integer number (15518997).

Almost surely, 2^51729985 is an apocalyptic number.

It is an amenable number.

51729985 is a deficient number, since it is larger than the sum of its proper divisors (10346003).

51729985 is a wasteful number, since it uses less digits than its factorization.

51729985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10346002.

The product of its digits is 226800, while the sum is 46.

The square root of 51729985 is about 7192.3560117669. The cubic root of 51729985 is about 372.6039467877.

The spelling of 51729985 in words is "fifty-one million, seven hundred twenty-nine thousand, nine hundred eighty-five".