821329672 has 8 divisors (see below), whose sum is σ = 1539993150. Its totient is φ = 410664832.

The previous prime is 821329661. The next prime is 821329679. The reversal of 821329672 is 276923128.

821329672 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 499701316 + 321628356 = 22354^2 + 17934^2 .

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

It is not an unprimeable number, because it can be changed into a prime (821329679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51333097 + ... + 51333112.

Almost surely, 2^821329672 is an apocalyptic number.

It is an amenable number.

821329672 is a deficient number, since it is larger than the sum of its proper divisors (718663478).

821329672 is a wasteful number, since it uses less digits than its factorization.

821329672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102666215 (or 102666211 counting only the distinct ones).

The product of its digits is 72576, while the sum is 40.

The square root of 821329672 is about 28658.8498024607. The cubic root of 821329672 is about 936.4958077656.

The spelling of 821329672 in words is "eight hundred twenty-one million, three hundred twenty-nine thousand, six hundred seventy-two".