84820909 has 4 divisors (see below), whose sum is σ = 87113404. Its totient is φ = 82528416.

The previous prime is 84820907. The next prime is 84820961. The reversal of 84820909 is 90902848.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 79744900 + 5076009 = 8930^2 + 2253^2 .

It is a cyclic number.

It is not a de Polignac number, because 84820909 - 2¹ = 84820907 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 (84820903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1146192 + ... + 1146265.

It is an arithmetic number, because the mean of its divisors is an integer number (21778351).

Almost surely, 2^84820909 is an apocalyptic number.

It is an amenable number.

84820909 is a deficient number, since it is larger than the sum of its proper divisors (2292495).

84820909 is a wasteful number, since it uses less digits than its factorization.

84820909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2292494.

The product of its (nonzero) digits is 41472, while the sum is 40.

The square root of 84820909 is about 9209.8267627573. The cubic root of 84820909 is about 439.3739529810.

The spelling of 84820909 in words is "eighty-four million, eight hundred twenty thousand, nine hundred nine".