261224280 has 96 divisors (see below), whose sum is σ = 865060560. Its totient is φ = 68340480.

The previous prime is 261224273. The next prime is 261224297. The reversal of 261224280 is 82422162.

It is a happy number.

261224280 is a `hidden beast` number, since 2 + 612 + 2 + 42 + 8 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 12235 + ... + 25925.

Almost surely, 2^261224280 is an apocalyptic number.

261224280 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 261224280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (432530280).

261224280 is an abundant number, since it is smaller than the sum of its proper divisors (603836280).

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

261224280 is a wasteful number, since it uses less digits than its factorization.

261224280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13761 (or 13754 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 261224280 is about 16162.4342226040. The cubic root of 261224280 is about 639.2506529137.

The spelling of 261224280 in words is "two hundred sixty-one million, two hundred twenty-four thousand, two hundred eighty".