83942821 has 4 divisors (see below), whose sum is σ = 88880652. Its totient is φ = 79004992.

The previous prime is 83942819. The next prime is 83942827. The reversal of 83942821 is 12824938.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 78588225 + 5354596 = 8865^2 + 2314^2 .

It is a cyclic number.

It is not a de Polignac number, because 83942821 - 2¹ = 83942819 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (83942827) 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, 2468890 + ... + 2468923.

It is an arithmetic number, because the mean of its divisors is an integer number (22220163).

Almost surely, 2^83942821 is an apocalyptic number.

It is an amenable number.

83942821 is a deficient number, since it is larger than the sum of its proper divisors (4937831).

83942821 is a wasteful number, since it uses less digits than its factorization.

83942821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4937830.

The product of its digits is 27648, while the sum is 37.

The square root of 83942821 is about 9162.0314887038. The cubic root of 83942821 is about 437.8525197959.

It can be divided in two parts, 839 and 42821, that added together give a triangular number (43660 = T₂₉₅).

The spelling of 83942821 in words is "eighty-three million, nine hundred forty-two thousand, eight hundred twenty-one".