261912647 has 8 divisors (see below), whose sum is σ = 264253200. Its totient is φ = 259580160.

The previous prime is 261912631. The next prime is 261912649. The reversal of 261912647 is 746219162.

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

It is a cyclic number.

It is not a de Polignac number, because 261912647 - 2⁴ = 261912631 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 261912647.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261912649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 76247 + ... + 79607.

It is an arithmetic number, because the mean of its divisors is an integer number (33031650).

Almost surely, 2^261912647 is an apocalyptic number.

261912647 is a deficient number, since it is larger than the sum of its proper divisors (2340553).

261912647 is a wasteful number, since it uses less digits than its factorization.

261912647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4033.

The product of its digits is 36288, while the sum is 38.

The square root of 261912647 is about 16183.7154881072. The cubic root of 261912647 is about 639.8116690324.

The spelling of 261912647 in words is "two hundred sixty-one million, nine hundred twelve thousand, six hundred forty-seven".