51486379928789 has 4 divisors (see below), whose sum is σ = 55446870692556. Its totient is φ = 47525889165024.

The previous prime is 51486379928771. The next prime is 51486379928813. The reversal of 51486379928789 is 98782997368415.

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

It can be written as a sum of positive squares in 2 ways, for example, as 26226126111025 + 25260253817764 = 5121145^2 + 5025958^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51486379928789 is a prime.

It is a super-2 number, since 2×51486379928789² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51486379928789.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51486379928189) 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, 1980245381864 + ... + 1980245381889.

It is an arithmetic number, because the mean of its divisors is an integer number (13861717673139).

Almost surely, 2^{51486379928789} is an apocalyptic number.

It is an amenable number.

51486379928789 is a deficient number, since it is larger than the sum of its proper divisors (3960490763767).

51486379928789 is a wasteful number, since it uses less digits than its factorization.

51486379928789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3960490763766.

The product of its digits is 13168189440, while the sum is 86.

The spelling of 51486379928789 in words is "fifty-one trillion, four hundred eighty-six billion, three hundred seventy-nine million, nine hundred twenty-eight thousand, seven hundred eighty-nine".