261952240 has 80 divisors (see below), whose sum is σ = 699419520. Its totient is φ = 90236160.

The previous prime is 261952231. The next prime is 261952241. The reversal of 261952240 is 42259162.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261952241) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8887 + ... + 24553.

It is an arithmetic number, because the mean of its divisors is an integer number (8742744).

Almost surely, 2^261952240 is an apocalyptic number.

261952240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261952240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (349709760).

261952240 is an abundant number, since it is smaller than the sum of its proper divisors (437467280).

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

261952240 is a wasteful number, since it uses less digits than its factorization.

261952240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15710 (or 15704 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 261952240 is about 16184.9386776719. The cubic root of 261952240 is about 639.8439072454.

The spelling of 261952240 in words is "two hundred sixty-one million, nine hundred fifty-two thousand, two hundred forty".