261324789 has 12 divisors (see below), whose sum is σ = 382988928. Its totient is φ = 158378440.

The previous prime is 261324787. The next prime is 261324851. The reversal of 261324789 is 987423162.

It is not a de Polignac number, because 261324789 - 2¹ = 261324787 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 261324789.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261324787) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 359589 + ... + 360314.

It is an arithmetic number, because the mean of its divisors is an integer number (31915744).

Almost surely, 2^261324789 is an apocalyptic number.

It is an amenable number.

261324789 is a deficient number, since it is larger than the sum of its proper divisors (121664139).

261324789 is a wasteful number, since it uses less digits than its factorization.

261324789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 719928 (or 719917 counting only the distinct ones).

The product of its digits is 145152, while the sum is 42.

The square root of 261324789 is about 16165.5432633735. The cubic root of 261324789 is about 639.3326287102.

The spelling of 261324789 in words is "two hundred sixty-one million, three hundred twenty-four thousand, seven hundred eighty-nine".