261312 has 28 divisors (see below), whose sum is σ = 691896. Its totient is φ = 87040.

The previous prime is 261301. The next prime is 261323. The reversal of 261312 is 213162.

It is an interprime number because it is at equal distance from previous prime (261301) and next prime (261323).

It is a super-2 number, since 2×261312² = 136567922688, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a nialpdrome in base 8.

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 261291 and 261300.

It is an unprimeable number.

261312 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 489 + ... + 872.

2²⁶¹³¹² is an apocalyptic number.

It is an amenable number.

261312 is an abundant number, since it is smaller than the sum of its proper divisors (430584).

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

261312 is a wasteful number, since it uses less digits than its factorization.

261312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1376 (or 1366 counting only the distinct ones).

The product of its digits is 72, while the sum is 15.

The square root of 261312 is about 511.1868542911. The cubic root of 261312 is about 63.9322199086.

Adding to 261312 its reverse (213162), we get a palindrome (474474).

The spelling of 261312 in words is "two hundred sixty-one thousand, three hundred twelve".