51505388687 has 2 divisors, whose sum is σ = 51505388688. Its totient is φ = 51505388686.

The previous prime is 51505388653. The next prime is 51505388719. The reversal of 51505388687 is 78688350515.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 51505388687 - 2¹⁶ = 51505323151 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51505381687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25752694343 + 25752694344.

It is an arithmetic number, because the mean of its divisors is an integer number (25752694344).

Almost surely, 2^51505388687 is an apocalyptic number.

51505388687 is a deficient number, since it is larger than the sum of its proper divisors (1).

51505388687 is an equidigital number, since it uses as much as digits as its factorization.

51505388687 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8064000, while the sum is 56.

The spelling of 51505388687 in words is "fifty-one billion, five hundred five million, three hundred eighty-eight thousand, six hundred eighty-seven".