261331351 has 2 divisors, whose sum is σ = 261331352. Its totient is φ = 261331350.

The previous prime is 261331349. The next prime is 261331373. The reversal of 261331351 is 153133162.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 261331351 - 2¹ = 261331349 is a prime.

Together with 261331349, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261331331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130665675 + 130665676.

It is an arithmetic number, because the mean of its divisors is an integer number (130665676).

Almost surely, 2^261331351 is an apocalyptic number.

261331351 is a deficient number, since it is larger than the sum of its proper divisors (1).

261331351 is an equidigital number, since it uses as much as digits as its factorization.

261331351 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1620, while the sum is 25.

The square root of 261331351 is about 16165.7462246566. The cubic root of 261331351 is about 639.3379799893.

The spelling of 261331351 in words is "two hundred sixty-one million, three hundred thirty-one thousand, three hundred fifty-one".