51481181 has 2 divisors, whose sum is σ = 51481182. Its totient is φ = 51481180.

The previous prime is 51481163. The next prime is 51481187. The reversal of 51481181 is 18118415.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 34916281 + 16564900 = 5909^2 + 4070^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51481181 is a prime.

It is a super-2 number, since 2×51481181² = 5300623994309522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51481187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25740590 + 25740591.

It is an arithmetic number, because the mean of its divisors is an integer number (25740591).

Almost surely, 2^51481181 is an apocalyptic number.

It is an amenable number.

51481181 is a deficient number, since it is larger than the sum of its proper divisors (1).

51481181 is an equidigital number, since it uses as much as digits as its factorization.

51481181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1280, while the sum is 29.

The square root of 51481181 is about 7175.0387455400. The cubic root of 51481181 is about 372.0056195436.

Adding to 51481181 its reverse (18118415), we get a palindrome (69599596).

The spelling of 51481181 in words is "fifty-one million, four hundred eighty-one thousand, one hundred eighty-one".