551316781 has 2 divisors, whose sum is σ = 551316782. Its totient is φ = 551316780.

The previous prime is 551316763. The next prime is 551316797. The reversal of 551316781 is 187613155.

551316781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 536617225 + 14699556 = 23165^2 + 3834^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-551316781 is a prime.

It is a super-2 number, since 2×551316781² = 607900386024403922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 551316781.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (551316581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 275658390 + 275658391.

It is an arithmetic number, because the mean of its divisors is an integer number (275658391).

Almost surely, 2^551316781 is an apocalyptic number.

It is an amenable number.

551316781 is a deficient number, since it is larger than the sum of its proper divisors (1).

551316781 is an equidigital number, since it uses as much as digits as its factorization.

551316781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25200, while the sum is 37.

The square root of 551316781 is about 23480.1358812082. The cubic root of 551316781 is about 819.9746080775.

The spelling of 551316781 in words is "five hundred fifty-one million, three hundred sixteen thousand, seven hundred eighty-one".