84091021 has 8 divisors (see below), whose sum is σ = 96160064. Its totient is φ = 72036000.

The previous prime is 84091009. The next prime is 84091031. The reversal of 84091021 is 12019048.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 84091021 - 2¹⁵ = 84058253 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (84091031) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19006 + ... + 23008.

It is an arithmetic number, because the mean of its divisors is an integer number (12020008).

Almost surely, 2^84091021 is an apocalyptic number.

It is an amenable number.

84091021 is a deficient number, since it is larger than the sum of its proper divisors (12069043).

84091021 is a wasteful number, since it uses less digits than its factorization.

84091021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7011.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 84091021 is about 9170.1156481257. The cubic root of 84091021 is about 438.1100426856.

Subtracting from 84091021 its sum of digits (25), we obtain a triangular number (84090996 = T₁₂₉₆₈).

The spelling of 84091021 in words is "eighty-four million, ninety-one thousand, twenty-one".