84631821 has 16 divisors (see below), whose sum is σ = 114476544. Its totient is φ = 55609344.

The previous prime is 84631817. The next prime is 84631853. The reversal of 84631821 is 12813648.

It is not a de Polignac number, because 84631821 - 2² = 84631817 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (84631621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 97636 + ... + 98498.

It is an arithmetic number, because the mean of its divisors is an integer number (7154784).

Almost surely, 2^84631821 is an apocalyptic number.

It is an amenable number.

84631821 is a deficient number, since it is larger than the sum of its proper divisors (29844723).

84631821 is a wasteful number, since it uses less digits than its factorization.

84631821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1300.

The product of its digits is 9216, while the sum is 33.

The square root of 84631821 is about 9199.5554783913. Note that the first 3 decimals coincide. The cubic root of 84631821 is about 439.0472168986.

The spelling of 84631821 in words is "eighty-four million, six hundred thirty-one thousand, eight hundred twenty-one".