84821939 has 4 divisors (see below), whose sum is σ = 84850656. Its totient is φ = 84793224.

The previous prime is 84821927. The next prime is 84821987. The reversal of 84821939 is 93912848.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 84821939 - 2⁴ = 84821923 is a prime.

It is a super-2 number, since 2×84821939² = 14389522671439442, which contains 22 as substring.

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 84821939.

It is not an unprimeable number, because it can be changed into a prime (84829939) 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, 9344 + ... + 16029.

It is an arithmetic number, because the mean of its divisors is an integer number (21212664).

Almost surely, 2^84821939 is an apocalyptic number.

84821939 is a deficient number, since it is larger than the sum of its proper divisors (28717).

84821939 is a wasteful number, since it uses less digits than its factorization.

84821939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28716.

The product of its digits is 124416, while the sum is 44.

The square root of 84821939 is about 9209.8826811203. The cubic root of 84821939 is about 439.3757314471.

Subtracting 84821939 from its reverse (93912848), we obtain a palindrome (9090909).

The spelling of 84821939 in words is "eighty-four million, eight hundred twenty-one thousand, nine hundred thirty-nine".