261365851 has 2 divisors, whose sum is σ = 261365852. Its totient is φ = 261365850.

The previous prime is 261365831. The next prime is 261365869. The reversal of 261365851 is 158563162.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 261365851 - 2¹¹ = 261363803 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 261365851.

It is not a weakly prime, because it can be changed into another prime (261365801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130682925 + 130682926.

It is an arithmetic number, because the mean of its divisors is an integer number (130682926).

Almost surely, 2^261365851 is an apocalyptic number.

261365851 is a deficient number, since it is larger than the sum of its proper divisors (1).

261365851 is an equidigital number, since it uses as much as digits as its factorization.

261365851 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 43200, while the sum is 37.

The square root of 261365851 is about 16166.8132605038. The cubic root of 261365851 is about 639.3661130977.

The spelling of 261365851 in words is "two hundred sixty-one million, three hundred sixty-five thousand, eight hundred fifty-one".