84415821 has 16 divisors (see below), whose sum is σ = 132784128. Its totient is φ = 46681200.

The previous prime is 84415789. The next prime is 84415847. The reversal of 84415821 is 12851448.

It is not a de Polignac number, because 84415821 - 2⁵ = 84415789 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (84415621) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 64185 + ... + 65486.

It is an arithmetic number, because the mean of its divisors is an integer number (8299008).

Almost surely, 2^84415821 is an apocalyptic number.

It is an amenable number.

84415821 is a deficient number, since it is larger than the sum of its proper divisors (48368307).

84415821 is a wasteful number, since it uses less digits than its factorization.

84415821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129712.

The product of its digits is 10240, while the sum is 33.

The square root of 84415821 is about 9187.8082805422. The cubic root of 84415821 is about 438.6733819669.

The spelling of 84415821 in words is "eighty-four million, four hundred fifteen thousand, eight hundred twenty-one".