51665012 has 18 divisors (see below), whose sum is σ = 105175602. Its totient is φ = 22142064.

The previous prime is 51665011. The next prime is 51665021. The reversal of 51665012 is 21056615.

It can be written as a sum of positive squares in only one way, i.e., 41654116 + 10010896 = 6454^2 + 3164^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51665011) 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 5 ways as a sum of consecutive naturals, for example, 131603 + ... + 131994.

It is an arithmetic number, because the mean of its divisors is an integer number (5843089).

Almost surely, 2^51665012 is an apocalyptic number.

It is an amenable number.

51665012 is an abundant number, since it is smaller than the sum of its proper divisors (53510590).

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

51665012 is a wasteful number, since it uses less digits than its factorization.

51665012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263615 (or 263606 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 51665012 is about 7187.8377833671. The cubic root of 51665012 is about 372.4478842453.

The spelling of 51665012 in words is "fifty-one million, six hundred sixty-five thousand, twelve".