261755731 has 2 divisors, whose sum is σ = 261755732. Its totient is φ = 261755730.

The previous prime is 261755729. The next prime is 261755773. The reversal of 261755731 is 137557162.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 261755731 - 2¹ = 261755729 is a prime.

It is a super-2 number, since 2×261755731² = 137032125422688722, which contains 22 as substring.

Together with 261755729, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (261755701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130877865 + 130877866.

It is an arithmetic number, because the mean of its divisors is an integer number (130877866).

Almost surely, 2^261755731 is an apocalyptic number.

261755731 is a deficient number, since it is larger than the sum of its proper divisors (1).

261755731 is an equidigital number, since it uses as much as digits as its factorization.

261755731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 44100, while the sum is 37.

The square root of 261755731 is about 16178.8668020971. The cubic root of 261755731 is about 639.6838697510.

The spelling of 261755731 in words is "two hundred sixty-one million, seven hundred fifty-five thousand, seven hundred thirty-one".