51621161 has 2 divisors, whose sum is σ = 51621162. Its totient is φ = 51621160.

The previous prime is 51621137. The next prime is 51621209. The reversal of 51621161 is 16112615.

51621161 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49000000 + 2621161 = 7000^2 + 1619^2 .

It is a cyclic number.

It is not a de Polignac number, because 51621161 - 2¹⁰ = 51620137 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is equal to p_3092504 and since 51621161 and 3092504 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (51621121) 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, 25810580 + 25810581.

It is an arithmetic number, because the mean of its divisors is an integer number (25810581).

Almost surely, 2^51621161 is an apocalyptic number.

It is an amenable number.

51621161 is a deficient number, since it is larger than the sum of its proper divisors (1).

51621161 is an equidigital number, since it uses as much as digits as its factorization.

51621161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 360, while the sum is 23.

The square root of 51621161 is about 7184.7867748459. The cubic root of 51621161 is about 372.3424819340.

Adding to 51621161 its reverse (16112615), we get a palindrome (67733776).

The spelling of 51621161 in words is "fifty-one million, six hundred twenty-one thousand, one hundred sixty-one".