261318312 has 96 divisors (see below), whose sum is σ = 738410400. Its totient is φ = 86577984.

The previous prime is 261318307. The next prime is 261318331. The reversal of 261318312 is 213813162.

It is a happy number.

261318312 is a `hidden beast` number, since 2 + 613 + 18 + 31 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

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

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, 444883 + ... + 445469.

It is an arithmetic number, because the mean of its divisors is an integer number (7691775).

Almost surely, 2^261318312 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261318312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (369205200).

261318312 is an abundant number, since it is smaller than the sum of its proper divisors (477092088).

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

261318312 is a wasteful number, since it uses less digits than its factorization.

261318312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 837 (or 821 counting only the distinct ones).

The product of its digits is 1728, while the sum is 27.

The square root of 261318312 is about 16165.3429286236. The cubic root of 261318312 is about 639.3273466604.

It can be divided in two parts, 26131 and 8312, that added together give a palindrome (34443).

The spelling of 261318312 in words is "two hundred sixty-one million, three hundred eighteen thousand, three hundred twelve".