51121251221 has 8 divisors (see below), whose sum is σ = 51662888640. Its totient is φ = 50580796768.

The previous prime is 51121251197. The next prime is 51121251227. The reversal of 51121251221 is 12215212115.

51121251221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51121251221 is a prime.

It is a super-3 number, since 3×51121251221³ (a number of 33 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51121251227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 208721 + ... + 381846.

It is an arithmetic number, because the mean of its divisors is an integer number (6457861080).

Almost surely, 2^51121251221 is an apocalyptic number.

It is an amenable number.

51121251221 is a deficient number, since it is larger than the sum of its proper divisors (541637419).

51121251221 is a wasteful number, since it uses less digits than its factorization.

51121251221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 591483.

The product of its digits is 400, while the sum is 23.

Adding to 51121251221 its reverse (12215212115), we get a palindrome (63336463336).

The spelling of 51121251221 in words is "fifty-one billion, one hundred twenty-one million, two hundred fifty-one thousand, two hundred twenty-one".