821138 has 8 divisors (see below), whose sum is σ = 1240320. Its totient is φ = 407700.

The previous prime is 821131. The next prime is 821143. The reversal of 821138 is 831128.

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

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (821131) by changing a digit.

821138 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 in 3 ways as a sum of consecutive naturals, for example, 1058 + ... + 1661.

It is an arithmetic number, because the mean of its divisors is an integer number (155040).

2⁸²¹¹³⁸ is an apocalyptic number.

821138 is a deficient number, since it is larger than the sum of its proper divisors (419182).

821138 is a wasteful number, since it uses less digits than its factorization.

821138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2872.

The product of its digits is 384, while the sum is 23.

The square root of 821138 is about 906.1666513396. The cubic root of 821138 is about 93.6422952737.

It can be divided in two parts, 821 and 138, that added together give a palindrome (959).

The spelling of 821138 in words is "eight hundred twenty-one thousand, one hundred thirty-eight".