83557821 has 8 divisors (see below), whose sum is σ = 111457024. Its totient is φ = 55681920.

The previous prime is 83557819. The next prime is 83557847. The reversal of 83557821 is 12875538.

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

It is not a de Polignac number, because 83557821 - 2¹ = 83557819 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 83557821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (83557811) 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, 5940 + ... + 14226.

It is an arithmetic number, because the mean of its divisors is an integer number (13932128).

Almost surely, 2^83557821 is an apocalyptic number.

It is an amenable number.

83557821 is a deficient number, since it is larger than the sum of its proper divisors (27899203).

83557821 is a wasteful number, since it uses less digits than its factorization.

83557821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11651.

The product of its digits is 67200, while the sum is 39.

The square root of 83557821 is about 9140.9967180828. The cubic root of 83557821 is about 437.1820967839.

The spelling of 83557821 in words is "eighty-three million, five hundred fifty-seven thousand, eight hundred twenty-one".