551786981 has 2 divisors, whose sum is σ = 551786982. Its totient is φ = 551786980.

The previous prime is 551786941. The next prime is 551786993. The reversal of 551786981 is 189687155.

551786981 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., 529414081 + 22372900 = 23009^2 + 4730^2 .

It is a cyclic number.

It is not a de Polignac number, because 551786981 - 2²² = 547592677 is a prime.

It is a super-2 number, since 2×551786981² = 608937744802188722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (551786941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 275893490 + 275893491.

It is an arithmetic number, because the mean of its divisors is an integer number (275893491).

Almost surely, 2^551786981 is an apocalyptic number.

It is an amenable number.

551786981 is a deficient number, since it is larger than the sum of its proper divisors (1).

551786981 is an equidigital number, since it uses as much as digits as its factorization.

551786981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 604800, while the sum is 50.

The square root of 551786981 is about 23490.1464661249. The cubic root of 551786981 is about 820.2076516547.

The spelling of 551786981 in words is "five hundred fifty-one million, seven hundred eighty-six thousand, nine hundred eighty-one".