261628 has 6 divisors (see below), whose sum is σ = 457856. Its totient is φ = 130812.

The previous prime is 261619. The next prime is 261631. The reversal of 261628 is 826162.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32700 + ... + 32707.

2²⁶¹⁶²⁸ is an apocalyptic number.

It is an amenable number.

261628 is a deficient number, since it is larger than the sum of its proper divisors (196228).

261628 is a wasteful number, since it uses less digits than its factorization.

261628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65411 (or 65409 counting only the distinct ones).

The product of its digits is 1152, while the sum is 25.

The square root of 261628 is about 511.4958455354. The cubic root of 261628 is about 63.9579802301.

It can be divided in two parts, 2 and 61628, that multiplied together give a triangular number (123256 = T₄₉₆).

The spelling of 261628 in words is "two hundred sixty-one thousand, six hundred twenty-eight".