84521819 has 4 divisors (see below), whose sum is σ = 84656400. Its totient is φ = 84387240.

The previous prime is 84521813. The next prime is 84521821. The reversal of 84521819 is 91812548.

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 84521819 - 2¹² = 84517723 is a prime.

It is a super-2 number, since 2×84521819² = 14287875774137522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (84521813) 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, 66344 + ... + 67605.

It is an arithmetic number, because the mean of its divisors is an integer number (21164100).

Almost surely, 2^84521819 is an apocalyptic number.

84521819 is a deficient number, since it is larger than the sum of its proper divisors (134581).

84521819 is a wasteful number, since it uses less digits than its factorization.

84521819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134580.

The product of its digits is 23040, while the sum is 38.

The square root of 84521819 is about 9193.5748759664. The cubic root of 84521819 is about 438.8569141215.

The spelling of 84521819 in words is "eighty-four million, five hundred twenty-one thousand, eight hundred nineteen".