84236421 has 4 divisors (see below), whose sum is σ = 112315232. Its totient is φ = 56157612.

The previous prime is 84236401. The next prime is 84236429. The reversal of 84236421 is 12463248.

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 not a de Polignac number, because 84236421 - 2⁵ = 84236389 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 (84236429) 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, 14039401 + ... + 14039406.

It is an arithmetic number, because the mean of its divisors is an integer number (28078808).

Almost surely, 2^84236421 is an apocalyptic number.

It is an amenable number.

84236421 is a deficient number, since it is larger than the sum of its proper divisors (28078811).

84236421 is a wasteful number, since it uses less digits than its factorization.

84236421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28078810.

The product of its digits is 9216, while the sum is 30.

The square root of 84236421 is about 9178.0401502717. The cubic root of 84236421 is about 438.3624062153.

Adding to 84236421 its reverse (12463248), we get a palindrome (96699669).

The spelling of 84236421 in words is "eighty-four million, two hundred thirty-six thousand, four hundred twenty-one".