51022781 has 2 divisors, whose sum is σ = 51022782. Its totient is φ = 51022780.

The previous prime is 51022759. The next prime is 51022817. The reversal of 51022781 is 18722015.

Together with next prime (51022817) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50993881 + 28900 = 7141^2 + 170^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51022781 is a prime.

It is a super-2 number, since 2×51022781² = 5206648361947922, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51022781.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51022481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25511390 + 25511391.

It is an arithmetic number, because the mean of its divisors is an integer number (25511391).

Almost surely, 2^51022781 is an apocalyptic number.

It is an amenable number.

51022781 is a deficient number, since it is larger than the sum of its proper divisors (1).

51022781 is an equidigital number, since it uses as much as digits as its factorization.

51022781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1120, while the sum is 26.

The square root of 51022781 is about 7143.0232394974. The cubic root of 51022781 is about 370.8981855297.

Adding to 51022781 its reverse (18722015), we get a palindrome (69744796).

The spelling of 51022781 in words is "fifty-one million, twenty-two thousand, seven hundred eighty-one".