261655207 has 4 divisors (see below), whose sum is σ = 285442056. Its totient is φ = 237868360.

The previous prime is 261655193. The next prime is 261655237. The reversal of 261655207 is 702556162.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261655207 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261655237) 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, 11893408 + ... + 11893429.

It is an arithmetic number, because the mean of its divisors is an integer number (71360514).

Almost surely, 2^261655207 is an apocalyptic number.

261655207 is a deficient number, since it is larger than the sum of its proper divisors (23786849).

261655207 is a wasteful number, since it uses less digits than its factorization.

261655207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23786848.

The product of its (nonzero) digits is 25200, while the sum is 34.

The square root of 261655207 is about 16175.7598585043. The cubic root of 261655207 is about 639.6019717482.

The spelling of 261655207 in words is "two hundred sixty-one million, six hundred fifty-five thousand, two hundred seven".