261984960 has 168 divisors, whose sum is σ = 954304416. Its totient is φ = 65740800.

The previous prime is 261984949. The next prime is 261984971. The reversal of 261984960 is 69489162.

It is a happy number.

261984960 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 (261984949) and next prime (261984971).

It is a super-2 number, since 2×261984960² = 137272238532403200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 46285 + ... + 51635.

Almost surely, 2^261984960 is an apocalyptic number.

261984960 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 261984960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (477152208).

261984960 is an abundant number, since it is smaller than the sum of its proper divisors (692319456).

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

261984960 is a wasteful number, since it uses less digits than its factorization.

261984960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5391 (or 5378 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 45.

The square root of 261984960 is about 16185.9494624196. The cubic root of 261984960 is about 639.8705467338.

The spelling of 261984960 in words is "two hundred sixty-one million, nine hundred eighty-four thousand, nine hundred sixty".