551243261 has 2 divisors, whose sum is σ = 551243262. Its totient is φ = 551243260.

The previous prime is 551243249. The next prime is 551243263. The reversal of 551243261 is 162342155.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 541446361 + 9796900 = 23269^2 + 3130^2 .

It is a cyclic number.

It is not a de Polignac number, because 551243261 - 2¹⁴ = 551226877 is a prime.

Together with 551243263, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (551243263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 275621630 + 275621631.

It is an arithmetic number, because the mean of its divisors is an integer number (275621631).

Almost surely, 2^551243261 is an apocalyptic number.

It is an amenable number.

551243261 is a deficient number, since it is larger than the sum of its proper divisors (1).

551243261 is an equidigital number, since it uses as much as digits as its factorization.

551243261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7200, while the sum is 29.

The square root of 551243261 is about 23478.5702503368. The cubic root of 551243261 is about 819.9381576403.

It can be divided in two parts, 55124 and 3261, that added together give a palindrome (58385).

The spelling of 551243261 in words is "five hundred fifty-one million, two hundred forty-three thousand, two hundred sixty-one".