261543316 has 12 divisors (see below), whose sum is σ = 458118388. Its totient is φ = 130652352.

The previous prime is 261543301. The next prime is 261543319. The reversal of 261543316 is 613345162.

It can be written as a sum of positive squares in 2 ways, for example, as 44275716 + 217267600 = 6654^2 + 14740^2 .

It is a super-2 number, since 2×261543316² = 136809812288551712, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261543319) 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, 24801 + ... + 33736.

Almost surely, 2^261543316 is an apocalyptic number.

It is an amenable number.

261543316 is a deficient number, since it is larger than the sum of its proper divisors (196575072).

261543316 is a wasteful number, since it uses less digits than its factorization.

261543316 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59658 (or 59656 counting only the distinct ones).

The product of its digits is 12960, while the sum is 31.

The square root of 261543316 is about 16172.3008876288. The cubic root of 261543316 is about 639.5107882545.

Adding to 261543316 its reverse (613345162), we get a palindrome (874888478).

The spelling of 261543316 in words is "two hundred sixty-one million, five hundred forty-three thousand, three hundred sixteen".