51647578567 has 4 divisors (see below), whose sum is σ = 55620469240. Its totient is φ = 47674687896.

The previous prime is 51647578561. The next prime is 51647578627. The reversal of 51647578567 is 76587574615.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51647578567 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 (51647578561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1986445317 + ... + 1986445342.

It is an arithmetic number, because the mean of its divisors is an integer number (13905117310).

Almost surely, 2^51647578567 is an apocalyptic number.

51647578567 is a deficient number, since it is larger than the sum of its proper divisors (3972890673).

51647578567 is a wasteful number, since it uses less digits than its factorization.

51647578567 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3972890672.

The product of its digits is 49392000, while the sum is 61.

The spelling of 51647578567 in words is "fifty-one billion, six hundred forty-seven million, five hundred seventy-eight thousand, five hundred sixty-seven".