261558806 has 16 divisors (see below), whose sum is σ = 410120928. Its totient is φ = 124872000.

The previous prime is 261558799. The next prime is 261558823. The reversal of 261558806 is 608855162.

261558806 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×261558806³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22916 + ... + 32376.

It is an arithmetic number, because the mean of its divisors is an integer number (25632558).

Almost surely, 2^261558806 is an apocalyptic number.

261558806 is a deficient number, since it is larger than the sum of its proper divisors (148562122).

261558806 is a wasteful number, since it uses less digits than its factorization.

261558806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10087.

The product of its (nonzero) digits is 115200, while the sum is 41.

The square root of 261558806 is about 16172.7797858006. The cubic root of 261558806 is about 639.5234130932.

The spelling of 261558806 in words is "two hundred sixty-one million, five hundred fifty-eight thousand, eight hundred six".