51551115551 has 4 divisors (see below), whose sum is σ = 55516585992. Its totient is φ = 47585645112.

The previous prime is 51551115547. The next prime is 51551115569. The reversal of 51551115551 is 15551115515.

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 51551115551 - 2² = 51551115547 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 (51551115151) 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, 1982735201 + ... + 1982735226.

It is an arithmetic number, because the mean of its divisors is an integer number (13879146498).

Almost surely, 2^51551115551 is an apocalyptic number.

51551115551 is a deficient number, since it is larger than the sum of its proper divisors (3965470441).

51551115551 is a wasteful number, since it uses less digits than its factorization.

51551115551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3965470440.

The product of its digits is 15625, while the sum is 35.

The spelling of 51551115551 in words is "fifty-one billion, five hundred fifty-one million, one hundred fifteen thousand, five hundred fifty-one".