85020816921 has 16 divisors (see below), whose sum is σ = 115555095936. Its totient is φ = 55584562176.

The previous prime is 85020816919. The next prime is 85020816953. The reversal of 85020816921 is 12961802058.

It is a happy number.

It is not a de Polignac number, because 85020816921 - 2¹ = 85020816919 is a prime.

It is not an unprimeable number, because it can be changed into a prime (85020816421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 209436 + ... + 462498.

It is an arithmetic number, because the mean of its divisors is an integer number (7222193496).

Almost surely, 2^85020816921 is an apocalyptic number.

It is an amenable number.

85020816921 is a deficient number, since it is larger than the sum of its proper divisors (30534279015).

85020816921 is a wasteful number, since it uses less digits than its factorization.

85020816921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255232.

The product of its (nonzero) digits is 69120, while the sum is 42.

The spelling of 85020816921 in words is "eighty-five billion, twenty million, eight hundred sixteen thousand, nine hundred twenty-one".