84391009 has 8 divisors (see below), whose sum is σ = 89466120. Its totient is φ = 79328256.

The previous prime is 84390973. The next prime is 84391019. The reversal of 84391009 is 90019348.

It can be written as a sum of positive squares in 4 ways, for example, as 45265984 + 39125025 = 6728^2 + 6255^2 .

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

It is not a de Polignac number, because 84391009 - 2¹⁹ = 83866721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (84391019) 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, 13597 + ... + 18805.

It is an arithmetic number, because the mean of its divisors is an integer number (11183265).

Almost surely, 2^84391009 is an apocalyptic number.

It is an amenable number.

84391009 is a deficient number, since it is larger than the sum of its proper divisors (5075111).

84391009 is a wasteful number, since it uses less digits than its factorization.

84391009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6179.

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 84391009 is about 9186.4579136901. The cubic root of 84391009 is about 438.6303985925.

The spelling of 84391009 in words is "eighty-four million, three hundred ninety-one thousand, nine".