261626 has 8 divisors (see below), whose sum is σ = 394740. Its totient is φ = 130048.

The previous prime is 261619. The next prime is 261631. The reversal of 261626 is 626162.

It can be written as a sum of positive squares in 2 ways, for example, as 201601 + 60025 = 449^2 + 245^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a nialpdrome in base 13.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 260 + ... + 768.

2²⁶¹⁶²⁶ is an apocalyptic number.

261626 is a deficient number, since it is larger than the sum of its proper divisors (133114).

261626 is a wasteful number, since it uses less digits than its factorization.

261626 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 768.

The product of its digits is 864, while the sum is 23.

The square root of 261626 is about 511.4938904816. The cubic root of 261626 is about 63.9578172553.

Adding to 261626 its reverse (626162), we get a palindrome (887788).

The spelling of 261626 in words is "two hundred sixty-one thousand, six hundred twenty-six".