261961678 has 8 divisors (see below), whose sum is σ = 428664600. Its totient is φ = 119073480.

The previous prime is 261961663. The next prime is 261961681. The reversal of 261961678 is 876169162.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5953653 + ... + 5953696.

It is an arithmetic number, because the mean of its divisors is an integer number (53583075).

Almost surely, 2^261961678 is an apocalyptic number.

261961678 is a deficient number, since it is larger than the sum of its proper divisors (166702922).

261961678 is a wasteful number, since it uses less digits than its factorization.

261961678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11907362.

The product of its digits is 217728, while the sum is 46.

The square root of 261961678 is about 16185.2302424155. The cubic root of 261961678 is about 639.8515915651.

The spelling of 261961678 in words is "two hundred sixty-one million, nine hundred sixty-one thousand, six hundred seventy-eight".