821378 has 8 divisors (see below), whose sum is σ = 1239420. Its totient is φ = 408240.

The previous prime is 821377. The next prime is 821383. The reversal of 821378 is 873128.

It can be written as a sum of positive squares in 2 ways, for example, as 537289 + 284089 = 733^2 + 533^2 .

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

It is a plaindrome in base 15.

It is a nialpdrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 821378.

It is not an unprimeable number, because it can be changed into a prime (821377) 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, 773 + ... + 1496.

2⁸²¹³⁷⁸ is an apocalyptic number.

821378 is a deficient number, since it is larger than the sum of its proper divisors (418042).

821378 is a wasteful number, since it uses less digits than its factorization.

821378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2452.

The product of its digits is 2688, while the sum is 29.

The square root of 821378 is about 906.2990676372. The cubic root of 821378 is about 93.6514175575.

The spelling of 821378 in words is "eight hundred twenty-one thousand, three hundred seventy-eight".