51280181 has 2 divisors, whose sum is σ = 51280182. Its totient is φ = 51280180.

The previous prime is 51280157. The next prime is 51280213. The reversal of 51280181 is 18108215.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 51251281 + 28900 = 7159^2 + 170^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51280181 is a prime.

It is a super-2 number, since 2×51280181² = 5259313926785522, which contains 22 as substring.

It is equal to p_3073238 and since 51280181 and 3073238 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51280181.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51280121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25640090 + 25640091.

It is an arithmetic number, because the mean of its divisors is an integer number (25640091).

Almost surely, 2^51280181 is an apocalyptic number.

It is an amenable number.

51280181 is a deficient number, since it is larger than the sum of its proper divisors (1).

51280181 is an equidigital number, since it uses as much as digits as its factorization.

51280181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 640, while the sum is 26.

The square root of 51280181 is about 7161.0181538661. The cubic root of 51280181 is about 371.5208426929.

Adding to 51280181 its reverse (18108215), we get a palindrome (69388396).

The spelling of 51280181 in words is "fifty-one million, two hundred eighty thousand, one hundred eighty-one".