1555261 has 2 divisors, whose sum is σ = 1555262. Its totient is φ = 1555260.

The previous prime is 1555259. The next prime is 1555289. The reversal of 1555261 is 1625551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 962361 + 592900 = 981^2 + 770^2 .

It is an emirp because it is prime and its reverse (1625551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1555261 - 2¹ = 1555259 is a prime.

Together with 1555259, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1555231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 777630 + 777631.

It is an arithmetic number, because the mean of its divisors is an integer number (777631).

2^1555261 is an apocalyptic number.

It is an amenable number.

1555261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1555261 is an equidigital number, since it uses as much as digits as its factorization.

1555261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1500, while the sum is 25.

The square root of 1555261 is about 1247.1010384087. The cubic root of 1555261 is about 115.8602409182.

The spelling of 1555261 in words is "one million, five hundred fifty-five thousand, two hundred sixty-one".