51139986 has 32 divisors (see below), whose sum is σ = 105135360. Its totient is φ = 16574544.

The previous prime is 51139981. The next prime is 51139999. The reversal of 51139986 is 68993115.

It is not an unprimeable number, because it can be changed into a prime (51139981) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 97521 + ... + 98043.

It is an arithmetic number, because the mean of its divisors is an integer number (3285480).

Almost surely, 2^51139986 is an apocalyptic number.

51139986 is an abundant number, since it is smaller than the sum of its proper divisors (53995374).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51139986 is a wasteful number, since it uses less digits than its factorization.

51139986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 950.

The product of its digits is 58320, while the sum is 42.

The square root of 51139986 is about 7151.2226926589. Note that the first 3 decimals coincide. The cubic root of 51139986 is about 371.1819664696.

It can be divided in two parts, 51139 and 986, that added together give a palindrome (52125).

The spelling of 51139986 in words is "fifty-one million, one hundred thirty-nine thousand, nine hundred eighty-six".