84105921 has 8 divisors (see below), whose sum is σ = 115172224. Its totient is φ = 54555120.

The previous prime is 84105899. The next prime is 84105929. The reversal of 84105921 is 12950148.

It is a happy number.

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

It is not a de Polignac number, because 84105921 - 2¹⁰ = 84104897 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (84105929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 378745 + ... + 378966.

It is an arithmetic number, because the mean of its divisors is an integer number (14396528).

Almost surely, 2^84105921 is an apocalyptic number.

It is an amenable number.

84105921 is a deficient number, since it is larger than the sum of its proper divisors (31066303).

84105921 is a wasteful number, since it uses less digits than its factorization.

84105921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 757751.

The product of its (nonzero) digits is 2880, while the sum is 30.

The square root of 84105921 is about 9170.9280337379. The cubic root of 84105921 is about 438.1359172441.

The spelling of 84105921 in words is "eighty-four million, one hundred five thousand, nine hundred twenty-one".