51565655291 has 4 divisors (see below), whose sum is σ = 51595830000. Its totient is φ = 51535480584.

The previous prime is 51565655287. The next prime is 51565655303. The reversal of 51565655291 is 19255656515.

51565655291 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, and also an emirpimes, since its reverse is a distinct semiprime: 19255656515 = 5 ⋅3851131303.

It is a cyclic number.

It is not a de Polignac number, because 51565655291 - 2² = 51565655287 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51565655201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15084791 + ... + 15088208.

It is an arithmetic number, because the mean of its divisors is an integer number (12898957500).

Almost surely, 2^51565655291 is an apocalyptic number.

51565655291 is a deficient number, since it is larger than the sum of its proper divisors (30174709).

51565655291 is a wasteful number, since it uses less digits than its factorization.

51565655291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30174708.

The product of its digits is 2025000, while the sum is 50.

The spelling of 51565655291 in words is "fifty-one billion, five hundred sixty-five million, six hundred fifty-five thousand, two hundred ninety-one".