1861261 has 2 divisors, whose sum is σ = 1861262. Its totient is φ = 1861260.

The previous prime is 1861253. The next prime is 1861267. The reversal of 1861261 is 1621681.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1716100 + 145161 = 1310^2 + 381^2 .

It is a cyclic number.

It is not a de Polignac number, because 1861261 - 2³ = 1861253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1861267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 930630 + 930631.

It is an arithmetic number, because the mean of its divisors is an integer number (930631).

2^1861261 is an apocalyptic number.

It is an amenable number.

1861261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1861261 is an equidigital number, since it uses as much as digits as its factorization.

1861261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 576, while the sum is 25.

The square root of 1861261 is about 1364.2803963995. The cubic root of 1861261 is about 123.0086802872.

The spelling of 1861261 in words is "one million, eight hundred sixty-one thousand, two hundred sixty-one".