261663106 has 8 divisors (see below), whose sum is σ = 393015420. Its totient is φ = 130657968.

The previous prime is 261663091. The next prime is 261663109. The reversal of 261663106 is 601366162.

It can be written as a sum of positive squares in 2 ways, for example, as 242082481 + 19580625 = 15559^2 + 4425^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (261663109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 84901 + ... + 87928.

Almost surely, 2^261663106 is an apocalyptic number.

261663106 is a deficient number, since it is larger than the sum of its proper divisors (131352314).

261663106 is a wasteful number, since it uses less digits than its factorization.

261663106 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173588.

The product of its (nonzero) digits is 7776, while the sum is 31.

The square root of 261663106 is about 16176.0040182982. The cubic root of 261663106 is about 639.6084079092.

The spelling of 261663106 in words is "two hundred sixty-one million, six hundred sixty-three thousand, one hundred six".