51256355551 has 4 divisors (see below), whose sum is σ = 52125107400. Its totient is φ = 50387603704.

The previous prime is 51256355543. The next prime is 51256355593. The reversal of 51256355551 is 15555365215.

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 51256355551 - 2³ = 51256355543 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51256355498 and 51256355507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51256355351) 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, 434375836 + ... + 434375953.

It is an arithmetic number, because the mean of its divisors is an integer number (13031276850).

Almost surely, 2^51256355551 is an apocalyptic number.

51256355551 is a deficient number, since it is larger than the sum of its proper divisors (868751849).

51256355551 is an equidigital number, since it uses as much as digits as its factorization.

51256355551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 868751848.

The product of its digits is 562500, while the sum is 43.

The spelling of 51256355551 in words is "fifty-one billion, two hundred fifty-six million, three hundred fifty-five thousand, five hundred fifty-one".