51564163643 has 4 divisors (see below), whose sum is σ = 51616942680. Its totient is φ = 51511384608.

The previous prime is 51564163621. The next prime is 51564163691. The reversal of 51564163643 is 34636146515.

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 51564163643 - 2¹² = 51564159547 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51564163594 and 51564163603.

It is not an unprimeable number, because it can be changed into a prime (51564165643) 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, 26388053 + ... + 26390006.

It is an arithmetic number, because the mean of its divisors is an integer number (12904235670).

Almost surely, 2^51564163643 is an apocalyptic number.

51564163643 is a deficient number, since it is larger than the sum of its proper divisors (52779037).

51564163643 is an equidigital number, since it uses as much as digits as its factorization.

51564163643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52779036.

The product of its digits is 777600, while the sum is 44.

The spelling of 51564163643 in words is "fifty-one billion, five hundred sixty-four million, one hundred sixty-three thousand, six hundred forty-three".