51383644561 has 4 divisors (see below), whose sum is σ = 51384262000. Its totient is φ = 51383027124.

The previous prime is 51383644553. The next prime is 51383644601. The reversal of 51383644561 is 16544638315.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16544638315 = 5 ⋅3308927663.

It is a cyclic number.

It is not a de Polignac number, because 51383644561 - 2³ = 51383644553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51383644261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 160011 + ... + 358288.

It is an arithmetic number, because the mean of its divisors is an integer number (12846065500).

Almost surely, 2^51383644561 is an apocalyptic number.

It is an amenable number.

51383644561 is a deficient number, since it is larger than the sum of its proper divisors (617439).

51383644561 is an equidigital number, since it uses as much as digits as its factorization.

51383644561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 617438.

The product of its digits is 1036800, while the sum is 46.

The spelling of 51383644561 in words is "fifty-one billion, three hundred eighty-three million, six hundred forty-four thousand, five hundred sixty-one".