83521 has 5 divisors (see below), whose sum is σ = 88741. Its totient is φ = 78608.

The previous prime is 83497. The next prime is 83537. The reversal of 83521 is 12538.

83521 = T₂₈₈ + T₂₈₉.

It is a happy number.

The square root of 83521 is 289.

It is a perfect power (a square, a biquadrate), and thus also a powerful number.

83521 is nontrivially palindromic in base 16.

It can be written as a sum of positive squares in 2 ways, for example, as 25921 + 57600 = 161^2 + 240^2 .

It is not a de Polignac number, because 83521 - 2⁹ = 83009 is a prime.

It is a Duffinian number.

83521 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (83561) by changing a digit.

It is a polite number, since it can be written in 4 ways as a sum of consecutive naturals, for example, 4905 + ... + 4921.

83521 is a Friedman number, since it can be written as (8+3^2)^(5-1), using all its digits and the basic arithmetic operations.

2⁸³⁵²¹ is an apocalyptic number.

83521 is the 289-th square number.

83521 is the 145-th centered octagonal number.

It is an amenable number.

83521 is a deficient number, since it is larger than the sum of its proper divisors (5220).

83521 is an frugal number, since it uses more digits than its factorization.

83521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68 (or 17 counting only the distinct ones).

The product of its digits is 240, while the sum is 19.

The cubic root of 83521 is about 43.7117870412.

The spelling of 83521 in words is "eighty-three thousand, five hundred twenty-one".