51109985 has 8 divisors (see below), whose sum is σ = 62828136. Its totient is φ = 39890560.

The previous prime is 51109969. The next prime is 51109997. The reversal of 51109985 is 58990115.

It can be written as a sum of positive squares in 4 ways, for example, as 1308736 + 49801249 = 1144^2 + 7057^2 .

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

It is not a de Polignac number, because 51109985 - 2⁴ = 51109969 is a prime.

It is a super-2 number, since 2×51109985² = 5224461133400450, which contains 22 as substring.

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 7 ways as a sum of consecutive naturals, for example, 124454 + ... + 124863.

It is an arithmetic number, because the mean of its divisors is an integer number (7853517).

Almost surely, 2^51109985 is an apocalyptic number.

It is an amenable number.

51109985 is a deficient number, since it is larger than the sum of its proper divisors (11718151).

51109985 is a wasteful number, since it uses less digits than its factorization.

51109985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249363.

The product of its (nonzero) digits is 16200, while the sum is 38.

The square root of 51109985 is about 7149.1247716067. The cubic root of 51109985 is about 371.1093682978.

The spelling of 51109985 in words is "fifty-one million, one hundred nine thousand, nine hundred eighty-five".