261412309 has 2 divisors, whose sum is σ = 261412310. Its totient is φ = 261412308.

The previous prime is 261412259. The next prime is 261412321. The reversal of 261412309 is 903214162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 222099409 + 39312900 = 14903^2 + 6270^2 .

It is a cyclic number.

It is not a de Polignac number, because 261412309 - 2¹⁵ = 261379541 is a prime.

It is a super-2 number, since 2×261412309² = 136672790593422962, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261412339) 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, 130706154 + 130706155.

It is an arithmetic number, because the mean of its divisors is an integer number (130706155).

Almost surely, 2^261412309 is an apocalyptic number.

It is an amenable number.

261412309 is a deficient number, since it is larger than the sum of its proper divisors (1).

261412309 is an equidigital number, since it uses as much as digits as its factorization.

261412309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 261412309 is about 16168.2500289920. The cubic root of 261412309 is about 639.4039934750.

The spelling of 261412309 in words is "two hundred sixty-one million, four hundred twelve thousand, three hundred nine".