83420821 has 4 divisors (see below), whose sum is σ = 91004544. Its totient is φ = 75837100.

The previous prime is 83420809. The next prime is 83420837. The reversal of 83420821 is 12802438.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 83420821 - 2⁵ = 83420789 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 83420821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (83420801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3791845 + ... + 3791866.

It is an arithmetic number, because the mean of its divisors is an integer number (22751136).

Almost surely, 2^83420821 is an apocalyptic number.

It is an amenable number.

83420821 is a deficient number, since it is larger than the sum of its proper divisors (7583723).

83420821 is a wasteful number, since it uses less digits than its factorization.

83420821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7583722.

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 83420821 is about 9133.4999315706. The cubic root of 83420821 is about 436.9430339406.

The spelling of 83420821 in words is "eighty-three million, four hundred twenty thousand, eight hundred twenty-one".