83521321 has 27 divisors (see below), whose sum is σ = 98100261. Its totient is φ = 71064864.

The previous prime is 83521307. The next prime is 83521337. The reversal of 83521321 is 12312538.

The square root of 83521321 is 9139.

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

It can be written as a sum of positive squares in 4 ways, for example, as 346921 + 83174400 = 589^2 + 9120^2 .

It is not a de Polignac number, because 83521321 - 2⁹ = 83520809 is a prime.

It is a super-2 number, since 2×83521321² = 13951622123170082, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (83521381) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 2257315 + ... + 2257351.

It is an arithmetic number, because the mean of its divisors is an integer number (3633343).

Almost surely, 2^83521321 is an apocalyptic number.

83521321 is the 9139-th square number.

83521321 is the 4570-th centered octagonal number.

It is an amenable number.

83521321 is a deficient number, since it is larger than the sum of its proper divisors (14578940).

83521321 is a wasteful number, since it uses less digits than its factorization.

83521321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138 (or 69 counting only the distinct ones).

The product of its digits is 1440, while the sum is 25.

The cubic root of 83521321 is about 437.1184304094.

Multiplying 83521321 by its sum of digits (25), we get a square (2088033025 = 45695²).

Adding to 83521321 its reverse (12312538), we get a palindrome (95833859).

The spelling of 83521321 in words is "eighty-three million, five hundred twenty-one thousand, three hundred twenty-one".