261968911 has 2 divisors, whose sum is σ = 261968912. Its totient is φ = 261968910.

The previous prime is 261968881. The next prime is 261968921. The reversal of 261968911 is 119869162.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 261968911 - 2²³ = 253580303 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261968921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130984455 + 130984456.

It is an arithmetic number, because the mean of its divisors is an integer number (130984456).

Almost surely, 2^261968911 is an apocalyptic number.

261968911 is a deficient number, since it is larger than the sum of its proper divisors (1).

261968911 is an equidigital number, since it uses as much as digits as its factorization.

261968911 is an evil number, because the sum of its binary digits is even.

The product of its digits is 46656, while the sum is 43.

The square root of 261968911 is about 16185.4536853312. The cubic root of 261968911 is about 639.8574804722.

The spelling of 261968911 in words is "two hundred sixty-one million, nine hundred sixty-eight thousand, nine hundred eleven".