261400 has 24 divisors (see below), whose sum is σ = 608220. Its totient is φ = 104480.

The previous prime is 261389. The next prime is 261407. The reversal of 261400 is 4162.

261400 = 90² + 91² + ... + 114².

261400 is nontrivially palindromic in base 3.

It is a nialpdrome in base 8.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 454 + ... + 853.

2²⁶¹⁴⁰⁰ is an apocalyptic number.

261400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261400 is an abundant number, since it is smaller than the sum of its proper divisors (346820).

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

261400 is a wasteful number, since it uses less digits than its factorization.

261400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1323 (or 1314 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 261400 is about 511.2729212466. The cubic root of 261400 is about 63.9393957544.

Adding to 261400 its reverse (4162), we get a palindrome (265562).

The spelling of 261400 in words is "two hundred sixty-one thousand, four hundred".