261661242 has 16 divisors (see below), whose sum is σ = 523595520. Its totient is φ = 87174912.

The previous prime is 261661241. The next prime is 261661243. The reversal of 261661242 is 242166162.

261661242 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (261661241) and next prime (261661243).

It is not an unprimeable number, because it can be changed into a prime (261661241) 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, 2359 + ... + 22997.

It is an arithmetic number, because the mean of its divisors is an integer number (32724720).

Almost surely, 2^261661242 is an apocalyptic number.

261661242 is an abundant number, since it is smaller than the sum of its proper divisors (261934278).

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

261661242 is a wasteful number, since it uses less digits than its factorization.

261661242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22757.

The product of its digits is 6912, while the sum is 30.

The square root of 261661242 is about 16175.9464019884. The cubic root of 261661242 is about 639.6068891205.

The spelling of 261661242 in words is "two hundred sixty-one million, six hundred sixty-one thousand, two hundred forty-two".