281961 has 15 divisors (see below), whose sum is σ = 428461.
Its totient is φ = 184788.
The previous prime is 281959. The next prime is 281971. The reversal of 281961 is 169182.
281961 = 382 + 392 + ... + 962.
The square root of 281961 is 531.
It is a perfect power (a square), and thus also a powerful number.
It is not a de Polignac number, because 281961 - 21 = 281959 is a prime.
It is a super-4 number, since 4×2819614 (a number of 23 digits) contains 4444 as substring.
It is a Harshad number since it is a multiple of its sum of digits (27).
It is a Duffinian number.
It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 281961.
It is not an unprimeable number, because it can be changed into a prime (281921) by changing a digit.
It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 4750 + ... + 4808.
281961 is a Friedman number, since it can be written as (9*(11+8*6))^2, using all its digits and the basic arithmetic operations.
2281961 is an apocalyptic number.
281961 is the 531-st square number.
281961 is the 266-th centered octagonal number.
It is an amenable number.
281961 is a deficient number, since it is larger than the sum of its proper divisors (146500).
281961 is an frugal number, since it uses more digits than its factorization.
281961 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 130 (or 62 counting only the distinct ones).
The product of its digits is 864, while the sum is 27.
The cubic root of 281961 is about 65.5736986820.
The spelling of 281961 in words is "two hundred eighty-one thousand, nine hundred sixty-one".