51213761 has 2 divisors, whose sum is σ = 51213762. Its totient is φ = 51213760.

The previous prime is 51213737. The next prime is 51213781. The reversal of 51213761 is 16731215.

51213761 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., 50481025 + 732736 = 7105^2 + 856^2 .

It is a cyclic number.

It is not a de Polignac number, because 51213761 - 2¹⁸ = 50951617 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51213761.

It is not a weakly prime, because it can be changed into another prime (51213781) 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, 25606880 + 25606881.

It is an arithmetic number, because the mean of its divisors is an integer number (25606881).

Almost surely, 2^51213761 is an apocalyptic number.

It is an amenable number.

51213761 is a deficient number, since it is larger than the sum of its proper divisors (1).

51213761 is an equidigital number, since it uses as much as digits as its factorization.

51213761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1260, while the sum is 26.

The square root of 51213761 is about 7156.3790425047. The cubic root of 51213761 is about 371.3603708465.

Adding to 51213761 its reverse (16731215), we get a palindrome (67944976).

The spelling of 51213761 in words is "fifty-one million, two hundred thirteen thousand, seven hundred sixty-one".