261672 has 16 divisors (see below), whose sum is σ = 654240. Its totient is φ = 87216.

The previous prime is 261643. The next prime is 261673. The reversal of 261672 is 276162.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (24), and also a Moran number because the ratio is a prime number: 10903 = 261672 / (2 + 6 + 1 + 6 + 7 + 2).

It is not an unprimeable number, because it can be changed into a prime (261673) by changing a digit.

261672 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 3 ways as a sum of consecutive naturals, for example, 5428 + ... + 5475.

It is an arithmetic number, because the mean of its divisors is an integer number (40890).

2²⁶¹⁶⁷² is an apocalyptic number.

It is an amenable number.

261672 is an abundant number, since it is smaller than the sum of its proper divisors (392568).

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

261672 is a wasteful number, since it uses less digits than its factorization.

261672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10912 (or 10908 counting only the distinct ones).

The product of its digits is 1008, while the sum is 24.

The square root of 261672 is about 511.5388548292. The cubic root of 261672 is about 63.9615654648.

The spelling of 261672 in words is "two hundred sixty-one thousand, six hundred seventy-two".