261109207 has 2 divisors, whose sum is σ = 261109208. Its totient is φ = 261109206.

The previous prime is 261109193. The next prime is 261109231. The reversal of 261109207 is 702901162.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261109207 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261109237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130554603 + 130554604.

It is an arithmetic number, because the mean of its divisors is an integer number (130554604).

Almost surely, 2^261109207 is an apocalyptic number.

261109207 is a deficient number, since it is larger than the sum of its proper divisors (1).

261109207 is an equidigital number, since it uses as much as digits as its factorization.

261109207 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1512, while the sum is 28.

The square root of 261109207 is about 16158.8739397274. The cubic root of 261109207 is about 639.1567728010.

The spelling of 261109207 in words is "two hundred sixty-one million, one hundred nine thousand, two hundred seven".