261310000 has 100 divisors (see below), whose sum is σ = 723230992. Its totient is φ = 89568000.

The previous prime is 261309967. The next prime is 261310003. The reversal of 261310000 is 13162.

It is a tau number, because it is divible by the number of its divisors (100).

It is a super-2 number, since 2×261310000² = 136565832200000000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261310003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 68134 + ... + 71866.

Almost surely, 2^261310000 is an apocalyptic number.

261310000 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 261310000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (361615496).

261310000 is an abundant number, since it is smaller than the sum of its proper divisors (461920992).

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

261310000 is an equidigital number, since it uses as much as digits as its factorization.

261310000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3768 (or 3747 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 261310000 is about 16165.0858333632. The cubic root of 261310000 is about 639.3205680243.

Adding to 261310000 its reverse (13162), we get a palindrome (261323162).

The spelling of 261310000 in words is "two hundred sixty-one million, three hundred ten thousand".