261786947 has 4 divisors (see below), whose sum is σ = 261960360. Its totient is φ = 261613536.

The previous prime is 261786919. The next prime is 261787013. The reversal of 261786947 is 749687162.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 261786947 - 2⁸ = 261786691 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261786895 and 261786904.

It is not an unprimeable number, because it can be changed into a prime (261782947) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 84422 + ... + 87467.

It is an arithmetic number, because the mean of its divisors is an integer number (65490090).

Almost surely, 2^261786947 is an apocalyptic number.

261786947 is a deficient number, since it is larger than the sum of its proper divisors (173413).

261786947 is a wasteful number, since it uses less digits than its factorization.

261786947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173412.

The product of its digits is 1016064, while the sum is 50.

The square root of 261786947 is about 16179.8314886157. The cubic root of 261786947 is about 639.7092975011.

The spelling of 261786947 in words is "two hundred sixty-one million, seven hundred eighty-six thousand, nine hundred forty-seven".