261405206 has 16 divisors (see below), whose sum is σ = 406809600. Its totient is φ = 125844840.

The previous prime is 261405187. The next prime is 261405239. The reversal of 261405206 is 602504162.

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, 1745 + ... + 22931.

It is an arithmetic number, because the mean of its divisors is an integer number (25425600).

Almost surely, 2^261405206 is an apocalyptic number.

261405206 is a deficient number, since it is larger than the sum of its proper divisors (145404394).

261405206 is a wasteful number, since it uses less digits than its factorization.

261405206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21419.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 261405206 is about 16168.0303686009. The cubic root of 261405206 is about 639.3982022051.

Adding to 261405206 its reverse (602504162), we get a palindrome (863909368).

The spelling of 261405206 in words is "two hundred sixty-one million, four hundred five thousand, two hundred six".