261338101 has 2 divisors, whose sum is σ = 261338102. Its totient is φ = 261338100.

The previous prime is 261338039. The next prime is 261338113. The reversal of 261338101 is 101833162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 253637476 + 7700625 = 15926^2 + 2775^2 .

It is a cyclic number.

It is not a de Polignac number, because 261338101 - 2²⁵ = 227783669 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261338171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130669050 + 130669051.

It is an arithmetic number, because the mean of its divisors is an integer number (130669051).

Almost surely, 2^261338101 is an apocalyptic number.

It is an amenable number.

261338101 is a deficient number, since it is larger than the sum of its proper divisors (1).

261338101 is an equidigital number, since it uses as much as digits as its factorization.

261338101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 261338101 is about 16165.9549980816. The cubic root of 261338101 is about 639.3434844879.

The spelling of 261338101 in words is "two hundred sixty-one million, three hundred thirty-eight thousand, one hundred one".