261866933 has 2 divisors, whose sum is σ = 261866934. Its totient is φ = 261866932.

The previous prime is 261866879. The next prime is 261866953. The reversal of 261866933 is 339668162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 169572484 + 92294449 = 13022^2 + 9607^2 .

It is a cyclic number.

It is not a de Polignac number, because 261866933 - 2⁸ = 261866677 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261866953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130933466 + 130933467.

It is an arithmetic number, because the mean of its divisors is an integer number (130933467).

Almost surely, 2^261866933 is an apocalyptic number.

It is an amenable number.

261866933 is a deficient number, since it is larger than the sum of its proper divisors (1).

261866933 is an equidigital number, since it uses as much as digits as its factorization.

261866933 is an evil number, because the sum of its binary digits is even.

The product of its digits is 279936, while the sum is 44.

The square root of 261866933 is about 16182.3030808349. The cubic root of 261866933 is about 639.7744428137.

The spelling of 261866933 in words is "two hundred sixty-one million, eight hundred sixty-six thousand, nine hundred thirty-three".