261774949 has 2 divisors, whose sum is σ = 261774950. Its totient is φ = 261774948.

The previous prime is 261774893. The next prime is 261774977. The reversal of 261774949 is 949477162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 137898049 + 123876900 = 11743^2 + 11130^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261774949 is a prime.

It is a super-2 number, since 2×261774949² = 137052247847905202, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261774649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130887474 + 130887475.

It is an arithmetic number, because the mean of its divisors is an integer number (130887475).

Almost surely, 2^261774949 is an apocalyptic number.

It is an amenable number.

261774949 is a deficient number, since it is larger than the sum of its proper divisors (1).

261774949 is an equidigital number, since it uses as much as digits as its factorization.

261774949 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 762048, while the sum is 49.

The square root of 261774949 is about 16179.4607141276. The cubic root of 261774949 is about 639.6995244783.

The spelling of 261774949 in words is "two hundred sixty-one million, seven hundred seventy-four thousand, nine hundred forty-nine".