51878581 has 2 divisors, whose sum is σ = 51878582. Its totient is φ = 51878580.

The previous prime is 51878579. The next prime is 51878587. The reversal of 51878581 is 18587815.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 51710481 + 168100 = 7191^2 + 410^2 .

It is a cyclic number.

It is not a de Polignac number, because 51878581 - 2¹ = 51878579 is a prime.

It is a super-2 number, since 2×51878581² = 5382774333147122, which contains 22 as substring.

Together with 51878579, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51878587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25939290 + 25939291.

It is an arithmetic number, because the mean of its divisors is an integer number (25939291).

Almost surely, 2^51878581 is an apocalyptic number.

It is an amenable number.

51878581 is a deficient number, since it is larger than the sum of its proper divisors (1).

51878581 is an equidigital number, since it uses as much as digits as its factorization.

51878581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 89600, while the sum is 43.

The square root of 51878581 is about 7202.6787378030. The cubic root of 51878581 is about 372.9603778827.

The spelling of 51878581 in words is "fifty-one million, eight hundred seventy-eight thousand, five hundred eighty-one".