51240861787 has 2 divisors, whose sum is σ = 51240861788. Its totient is φ = 51240861786.

The previous prime is 51240861773. The next prime is 51240861817. The reversal of 51240861787 is 78716804215.

51240861787 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51240861787 - 2¹⁵ = 51240829019 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51240861787.

It is not a weakly prime, because it can be changed into another prime (51240861487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25620430893 + 25620430894.

It is an arithmetic number, because the mean of its divisors is an integer number (25620430894).

Almost surely, 2^51240861787 is an apocalyptic number.

51240861787 is a deficient number, since it is larger than the sum of its proper divisors (1).

51240861787 is an equidigital number, since it uses as much as digits as its factorization.

51240861787 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 752640, while the sum is 49.

The spelling of 51240861787 in words is "fifty-one billion, two hundred forty million, eight hundred sixty-one thousand, seven hundred eighty-seven".