51221211101 has 2 divisors, whose sum is σ = 51221211102. Its totient is φ = 51221211100.

The previous prime is 51221211079. The next prime is 51221211127. The reversal of 51221211101 is 10111212215.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 43699812025 + 7521399076 = 209045^2 + 86726^2 .

It is a cyclic number.

It is not a de Polignac number, because 51221211101 - 2⁶ = 51221211037 is a prime.

It is a super-2 number, since 2×51221211101² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 51221211101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51221217101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25610605550 + 25610605551.

It is an arithmetic number, because the mean of its divisors is an integer number (25610605551).

Almost surely, 2^51221211101 is an apocalyptic number.

It is an amenable number.

51221211101 is a deficient number, since it is larger than the sum of its proper divisors (1).

51221211101 is an equidigital number, since it uses as much as digits as its factorization.

51221211101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40, while the sum is 17.

Adding to 51221211101 its reverse (10111212215), we get a palindrome (61332423316).

The spelling of 51221211101 in words is "fifty-one billion, two hundred twenty-one million, two hundred eleven thousand, one hundred one".