83218521 has 8 divisors (see below), whose sum is σ = 112362880. Its totient is φ = 54776592.

The previous prime is 83218517. The next prime is 83218543. The reversal of 83218521 is 12581238.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 83218521 - 2² = 83218517 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (83218571) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 175330 + ... + 175803.

It is an arithmetic number, because the mean of its divisors is an integer number (14045360).

Almost surely, 2^83218521 is an apocalyptic number.

It is an amenable number.

83218521 is a deficient number, since it is larger than the sum of its proper divisors (29144359).

83218521 is a wasteful number, since it uses less digits than its factorization.

83218521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 351215.

The product of its digits is 3840, while the sum is 30.

The square root of 83218521 is about 9122.4185937722. The cubic root of 83218521 is about 436.5895445511.

Adding to 83218521 its reverse (12581238), we get a palindrome (95799759).

The spelling of 83218521 in words is "eighty-three million, two hundred eighteen thousand, five hundred twenty-one".