261009912 has 16 divisors (see below), whose sum is σ = 652524840. Its totient is φ = 87003296.

The previous prime is 261009907. The next prime is 261009913. The reversal of 261009912 is 219900162.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 261009912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261009913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5437683 + ... + 5437730.

Almost surely, 2^261009912 is an apocalyptic number.

It is an amenable number.

261009912 is an abundant number, since it is smaller than the sum of its proper divisors (391514928).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261009912 is a wasteful number, since it uses less digits than its factorization.

261009912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10875422 (or 10875418 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 261009912 is about 16155.8011871897. The cubic root of 261009912 is about 639.0757426974.

The spelling of 261009912 in words is "two hundred sixty-one million, nine thousand, nine hundred twelve".