51208765 has 4 divisors (see below), whose sum is σ = 61450524. Its totient is φ = 40967008.

The previous prime is 51208763. The next prime is 51208783. The reversal of 51208765 is 56780215.

51208765 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 22629049 + 28579716 = 4757^2 + 5346^2 .

It is a cyclic number.

It is not a de Polignac number, because 51208765 - 2¹ = 51208763 is a prime.

It is a super-2 number, since 2×51208765² = 5244675225650450, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51208765.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51208763) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5120872 + ... + 5120881.

It is an arithmetic number, because the mean of its divisors is an integer number (15362631).

Almost surely, 2^51208765 is an apocalyptic number.

It is an amenable number.

51208765 is a deficient number, since it is larger than the sum of its proper divisors (10241759).

51208765 is a wasteful number, since it uses less digits than its factorization.

51208765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10241758.

The product of its (nonzero) digits is 16800, while the sum is 34.

The square root of 51208765 is about 7156.0299747835. The cubic root of 51208765 is about 371.3482948165.

The spelling of 51208765 in words is "fifty-one million, two hundred eight thousand, seven hundred sixty-five".