51212081 has 2 divisors, whose sum is σ = 51212082. Its totient is φ = 51212080.

The previous prime is 51212071. The next prime is 51212101. The reversal of 51212081 is 18021215.

It is a happy number.

It is an a-pointer prime, because the next prime (51212101) can be obtained adding 51212081 to its sum of digits (20).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 47541025 + 3671056 = 6895^2 + 1916^2 .

It is a cyclic number.

It is not a de Polignac number, because 51212081 - 2¹⁸ = 50949937 is a prime.

It is a super-2 number, since 2×51212081² = 5245354480701122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (51212071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25606040 + 25606041.

It is an arithmetic number, because the mean of its divisors is an integer number (25606041).

Almost surely, 2^51212081 is an apocalyptic number.

It is an amenable number.

51212081 is a deficient number, since it is larger than the sum of its proper divisors (1).

51212081 is an equidigital number, since it uses as much as digits as its factorization.

51212081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 160, while the sum is 20.

The square root of 51212081 is about 7156.2616637460. The cubic root of 51212081 is about 371.3563101395.

Adding to 51212081 its reverse (18021215), we get a palindrome (69233296).

The spelling of 51212081 in words is "fifty-one million, two hundred twelve thousand, eighty-one".