51360260221 has 4 divisors (see below), whose sum is σ = 51512664892. Its totient is φ = 51207855552.

The previous prime is 51360260213. The next prime is 51360260227. The reversal of 51360260221 is 12206206315.

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 19251562500 + 32108697721 = 138750^2 + 179189^2 .

It is a cyclic number.

It is not a de Polignac number, because 51360260221 - 2³ = 51360260213 is a prime.

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 51360260221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51360260227) 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, 76201830 + ... + 76202503.

It is an arithmetic number, because the mean of its divisors is an integer number (12878166223).

Almost surely, 2^51360260221 is an apocalyptic number.

It is an amenable number.

51360260221 is a deficient number, since it is larger than the sum of its proper divisors (152404671).

51360260221 is a wasteful number, since it uses less digits than its factorization.

51360260221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152404670.

The product of its (nonzero) digits is 4320, while the sum is 28.

Adding to 51360260221 its reverse (12206206315), we get a palindrome (63566466536).

The spelling of 51360260221 in words is "fifty-one billion, three hundred sixty million, two hundred sixty thousand, two hundred twenty-one".