51280681 has 2 divisors, whose sum is σ = 51280682. Its totient is φ = 51280680.

The previous prime is 51280667. The next prime is 51280693. The reversal of 51280681 is 18608215.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49632025 + 1648656 = 7045^2 + 1284^2 .

It is a cyclic number.

It is not a de Polignac number, because 51280681 - 2¹³ = 51272489 is a prime.

It is a super-2 number, since 2×51280681² = 5259416487647522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (51280181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25640340 + 25640341.

It is an arithmetic number, because the mean of its divisors is an integer number (25640341).

Almost surely, 2^51280681 is an apocalyptic number.

It is an amenable number.

51280681 is a deficient number, since it is larger than the sum of its proper divisors (1).

51280681 is an equidigital number, since it uses as much as digits as its factorization.

51280681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3840, while the sum is 31.

The square root of 51280681 is about 7161.0530650177. The cubic root of 51280681 is about 371.5220501758.

Adding to 51280681 its reverse (18608215), we get a palindrome (69888896).

The spelling of 51280681 in words is "fifty-one million, two hundred eighty thousand, six hundred eighty-one".