261311077 has 2 divisors, whose sum is σ = 261311078. Its totient is φ = 261311076.

The previous prime is 261310993. The next prime is 261311093. The reversal of 261311077 is 770113162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 252364996 + 8946081 = 15886^2 + 2991^2 .

It is a cyclic number.

It is not a de Polignac number, because 261311077 - 2⁷ = 261310949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261311377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130655538 + 130655539.

It is an arithmetic number, because the mean of its divisors is an integer number (130655539).

Almost surely, 2^261311077 is an apocalyptic number.

It is an amenable number.

261311077 is a deficient number, since it is larger than the sum of its proper divisors (1).

261311077 is an equidigital number, since it uses as much as digits as its factorization.

261311077 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1764, while the sum is 28.

The square root of 261311077 is about 16165.1191458647. The cubic root of 261311077 is about 639.3214463518.

The spelling of 261311077 in words is "two hundred sixty-one million, three hundred eleven thousand, seventy-seven".