821608 has 8 divisors (see below), whose sum is σ = 1540530. Its totient is φ = 410800.

The previous prime is 821603. The next prime is 821641. The reversal of 821608 is 806128.

It can be written as a sum of positive squares in only one way, i.e., 675684 + 145924 = 822^2 + 382^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (821603) by changing a digit.

821608 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51343 + ... + 51358.

2⁸²¹⁶⁰⁸ is an apocalyptic number.

It is an amenable number.

821608 is a deficient number, since it is larger than the sum of its proper divisors (718922).

821608 is a wasteful number, since it uses less digits than its factorization.

821608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102707 (or 102703 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 821608 is about 906.4259484370. The cubic root of 821608 is about 93.6601580789.

The spelling of 821608 in words is "eight hundred twenty-one thousand, six hundred eight".