51242561 has 2 divisors, whose sum is σ = 51242562. Its totient is φ = 51242560.

The previous prime is 51242533. The next prime is 51242567. The reversal of 51242561 is 16524215.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51208336 + 34225 = 7156^2 + 185^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51242561 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51242561.

It is not a weakly prime, because it can be changed into another prime (51242567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25621280 + 25621281.

It is an arithmetic number, because the mean of its divisors is an integer number (25621281).

Almost surely, 2^51242561 is an apocalyptic number.

It is an amenable number.

51242561 is a deficient number, since it is larger than the sum of its proper divisors (1).

51242561 is an equidigital number, since it uses as much as digits as its factorization.

51242561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2400, while the sum is 26.

The square root of 51242561 is about 7158.3909504860. The cubic root of 51242561 is about 371.4299691621.

Adding to 51242561 its reverse (16524215), we get a palindrome (67766776).

The spelling of 51242561 in words is "fifty-one million, two hundred forty-two thousand, five hundred sixty-one".