51240861791 has 4 divisors (see below), whose sum is σ = 58560984912. Its totient is φ = 43920738672.

The previous prime is 51240861787. The next prime is 51240861817. The reversal of 51240861791 is 19716804215.

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

It is a cyclic number.

It is not a de Polignac number, because 51240861791 - 2² = 51240861787 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51240861731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3660061550 + ... + 3660061563.

It is an arithmetic number, because the mean of its divisors is an integer number (14640246228).

Almost surely, 2^51240861791 is an apocalyptic number.

51240861791 is a deficient number, since it is larger than the sum of its proper divisors (7320123121).

51240861791 is an equidigital number, since it uses as much as digits as its factorization.

51240861791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7320123120.

The product of its (nonzero) digits is 120960, while the sum is 44.

The spelling of 51240861791 in words is "fifty-one billion, two hundred forty million, eight hundred sixty-one thousand, seven hundred ninety-one".