51721442177 has 4 divisors (see below), whose sum is σ = 52068566100. Its totient is φ = 51374318256.

The previous prime is 51721442161. The next prime is 51721442219. The reversal of 51721442177 is 77124412715.

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 10678328896 + 41043113281 = 103336^2 + 202591^2 .

It is a cyclic number.

It is not a de Polignac number, because 51721442177 - 2⁴ = 51721442161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51721442117) 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, 173561738 + ... + 173562035.

It is an arithmetic number, because the mean of its divisors is an integer number (13017141525).

Almost surely, 2^51721442177 is an apocalyptic number.

It is an amenable number.

51721442177 is a deficient number, since it is larger than the sum of its proper divisors (347123923).

51721442177 is a wasteful number, since it uses less digits than its factorization.

51721442177 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 347123922.

The product of its digits is 109760, while the sum is 41.

The spelling of 51721442177 in words is "fifty-one billion, seven hundred twenty-one million, four hundred forty-two thousand, one hundred seventy-seven".