51250081 has 2 divisors, whose sum is σ = 51250082. Its totient is φ = 51250080.

The previous prime is 51250061. The next prime is 51250091. The reversal of 51250081 is 18005215.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48427681 + 2822400 = 6959^2 + 1680^2 .

It is a cyclic number.

It is not a de Polignac number, because 51250081 - 2¹¹ = 51248033 is a prime.

It is a super-2 number, since 2×51250081² = 5253141605013122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (51250061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25625040 + 25625041.

It is an arithmetic number, because the mean of its divisors is an integer number (25625041).

Almost surely, 2^51250081 is an apocalyptic number.

It is an amenable number.

51250081 is a deficient number, since it is larger than the sum of its proper divisors (1).

51250081 is an equidigital number, since it uses as much as digits as its factorization.

51250081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 400, while the sum is 22.

The square root of 51250081 is about 7158.9161889213. The cubic root of 51250081 is about 371.4481377619.

Adding to 51250081 its reverse (18005215), we get a palindrome (69255296).

The spelling of 51250081 in words is "fifty-one million, two hundred fifty thousand, eighty-one".