84109819 has 4 divisors (see below), whose sum is σ = 86161320. Its totient is φ = 82058320.

The previous prime is 84109813. The next prime is 84109841. The reversal of 84109819 is 91890148.

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

It is a cyclic number.

It is not a de Polignac number, because 84109819 - 2⁵ = 84109787 is a prime.

It is a super-2 number, since 2×84109819² = 14148923304425522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (84109813) 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, 1025689 + ... + 1025770.

It is an arithmetic number, because the mean of its divisors is an integer number (21540330).

Almost surely, 2^84109819 is an apocalyptic number.

84109819 is a deficient number, since it is larger than the sum of its proper divisors (2051501).

84109819 is a wasteful number, since it uses less digits than its factorization.

84109819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2051500.

The product of its (nonzero) digits is 20736, while the sum is 40.

The square root of 84109819 is about 9171.1405506622. The cubic root of 84109819 is about 438.1426858021.

The spelling of 84109819 in words is "eighty-four million, one hundred nine thousand, eight hundred nineteen".