821234138 has 8 divisors (see below), whose sum is σ = 1249201440. Its totient is φ = 404833660.

The previous prime is 821234137. The next prime is 821234177. The reversal of 821234138 is 831432128.

821234138 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (821234137) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2891528 + ... + 2891811.

It is an arithmetic number, because the mean of its divisors is an integer number (156150180).

Almost surely, 2^821234138 is an apocalyptic number.

821234138 is a deficient number, since it is larger than the sum of its proper divisors (427967302).

821234138 is a wasteful number, since it uses less digits than its factorization.

821234138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5783412.

The product of its digits is 9216, while the sum is 32.

The square root of 821234138 is about 28657.1830088025. The cubic root of 821234138 is about 936.4594964594.

The spelling of 821234138 in words is "eight hundred twenty-one million, two hundred thirty-four thousand, one hundred thirty-eight".