551111261 has 2 divisors, whose sum is σ = 551111262. Its totient is φ = 551111260.

The previous prime is 551111233. The next prime is 551111269. The reversal of 551111261 is 162111155.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 432432025 + 118679236 = 20795^2 + 10894^2 .

It is a cyclic number.

It is not a de Polignac number, because 551111261 - 2²⁶ = 484002397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (551111269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 275555630 + 275555631.

It is an arithmetic number, because the mean of its divisors is an integer number (275555631).

Almost surely, 2^551111261 is an apocalyptic number.

It is an amenable number.

551111261 is a deficient number, since it is larger than the sum of its proper divisors (1).

551111261 is an equidigital number, since it uses as much as digits as its factorization.

551111261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 300, while the sum is 23.

The square root of 551111261 is about 23475.7590079639. The cubic root of 551111261 is about 819.8727053046.

The spelling of 551111261 in words is "five hundred fifty-one million, one hundred eleven thousand, two hundred sixty-one".