84983109807821 has 4 divisors (see below), whose sum is σ = 85093621004700. Its totient is φ = 84872598610944.

The previous prime is 84983109807803. The next prime is 84983109807823. The reversal of 84983109807821 is 12870890138948.

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

It can be written as a sum of positive squares in 2 ways, for example, as 10017193350025 + 74965916457796 = 3164995^2 + 8658286^2 .

It is a cyclic number.

It is not a de Polignac number, because 84983109807821 - 2¹⁰ = 84983109806797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (84983109807823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55255597286 + ... + 55255598823.

It is an arithmetic number, because the mean of its divisors is an integer number (21273405251175).

Almost surely, 2^{84983109807821} is an apocalyptic number.

It is an amenable number.

84983109807821 is a deficient number, since it is larger than the sum of its proper divisors (110511196879).

84983109807821 is a wasteful number, since it uses less digits than its factorization.

84983109807821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110511196878.

The product of its (nonzero) digits is 55738368, while the sum is 68.

The spelling of 84983109807821 in words is "eighty-four trillion, nine hundred eighty-three billion, one hundred nine million, eight hundred seven thousand, eight hundred twenty-one".