84900821 has 2 divisors, whose sum is σ = 84900822. Its totient is φ = 84900820.

The previous prime is 84900817. The next prime is 84900833. The reversal of 84900821 is 12800948.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 84897796 + 3025 = 9214^2 + 55^2 .

It is a cyclic number.

It is not a de Polignac number, because 84900821 - 2² = 84900817 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84900811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42450410 + 42450411.

It is an arithmetic number, because the mean of its divisors is an integer number (42450411).

Almost surely, 2^84900821 is an apocalyptic number.

It is an amenable number.

84900821 is a deficient number, since it is larger than the sum of its proper divisors (1).

84900821 is an equidigital number, since it uses as much as digits as its factorization.

84900821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 84900821 is about 9214.1641509146. The cubic root of 84900821 is about 439.5118915746.

The spelling of 84900821 in words is "eighty-four million, nine hundred thousand, eight hundred twenty-one".