261018280 has 16 divisors (see below), whose sum is σ = 587291220. Its totient is φ = 104407296.

The previous prime is 261018271. The next prime is 261018287. The reversal of 261018280 is 82810162.

It can be written as a sum of positive squares in 2 ways, for example, as 260951716 + 66564 = 16154^2 + 258^2 .

It is not an unprimeable number, because it can be changed into a prime (261018287) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3262689 + ... + 3262768.

Almost surely, 2^261018280 is an apocalyptic number.

261018280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261018280 is an abundant number, since it is smaller than the sum of its proper divisors (326272940).

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

261018280 is a wasteful number, since it uses less digits than its factorization.

261018280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6525468 (or 6525464 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 28.

The square root of 261018280 is about 16156.0601632948. The cubic root of 261018280 is about 639.0825722320.

The spelling of 261018280 in words is "two hundred sixty-one million, eighteen thousand, two hundred eighty".