821916085 has 16 divisors (see below), whose sum is σ = 1047085056. Its totient is φ = 617214208.

The previous prime is 821916059. The next prime is 821916089. The reversal of 821916085 is 580619128.

It is a cyclic number.

It is not a de Polignac number, because 821916085 - 2¹³ = 821907893 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 (821916089) 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, 19932 + ... + 45178.

It is an arithmetic number, because the mean of its divisors is an integer number (65442816).

Almost surely, 2^821916085 is an apocalyptic number.

821916085 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

821916085 is a deficient number, since it is larger than the sum of its proper divisors (225168971).

821916085 is a wasteful number, since it uses less digits than its factorization.

821916085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25652.

The product of its (nonzero) digits is 34560, while the sum is 40.

The square root of 821916085 is about 28669.0789004460. The cubic root of 821916085 is about 936.7186345171.

The spelling of 821916085 in words is "eight hundred twenty-one million, nine hundred sixteen thousand, eighty-five".