51113221 has 2 divisors, whose sum is σ = 51113222. Its totient is φ = 51113220.

The previous prime is 51113207. The next prime is 51113233. The reversal of 51113221 is 12231115.

51113221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28740321 + 22372900 = 5361^2 + 4730^2 .

It is a cyclic number.

It is not a de Polignac number, because 51113221 - 2⁷ = 51113093 is a prime.

It is a super-2 number, since 2×51113221² = 5225122721989682, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 51113195 and 51113204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51113281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25556610 + 25556611.

It is an arithmetic number, because the mean of its divisors is an integer number (25556611).

Almost surely, 2^51113221 is an apocalyptic number.

It is an amenable number.

51113221 is a deficient number, since it is larger than the sum of its proper divisors (1).

51113221 is an equidigital number, since it uses as much as digits as its factorization.

51113221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60, while the sum is 16.

The square root of 51113221 is about 7149.3510894346. The cubic root of 51113221 is about 371.1172003262.

Adding to 51113221 its reverse (12231115), we get a palindrome (63344336).

The spelling of 51113221 in words is "fifty-one million, one hundred thirteen thousand, two hundred twenty-one".