261378207 has 12 divisors (see below), whose sum is σ = 378602640. Its totient is φ = 173764608.

The previous prime is 261378167. The next prime is 261378253. The reversal of 261378207 is 702873162.

261378207 is a `hidden beast` number, since 261 + 378 + 20 + 7 = 666.

It is not a de Polignac number, because 261378207 - 2²⁰ = 260329631 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261378277) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 37218 + ... + 43679.

It is an arithmetic number, because the mean of its divisors is an integer number (31550220).

Almost surely, 2^261378207 is an apocalyptic number.

261378207 is a deficient number, since it is larger than the sum of its proper divisors (117224433).

261378207 is a wasteful number, since it uses less digits than its factorization.

261378207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81262 (or 81259 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 36.

The square root of 261378207 is about 16167.1953968522. The cubic root of 261378207 is about 639.3761882257.

The spelling of 261378207 in words is "two hundred sixty-one million, three hundred seventy-eight thousand, two hundred seven".