821361 has 4 divisors (see below), whose sum is σ = 1095152. Its totient is φ = 547572.

The previous prime is 821333. The next prime is 821377. The reversal of 821361 is 163128.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 821361 - 2⁵ = 821329 is a prime.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

It is a nialpdrome in base 16.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 821361.

It is not an unprimeable number, because it can be changed into a prime (821311) 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, 136891 + ... + 136896.

It is an arithmetic number, because the mean of its divisors is an integer number (273788).

2⁸²¹³⁶¹ is an apocalyptic number.

It is an amenable number.

821361 is a deficient number, since it is larger than the sum of its proper divisors (273791).

821361 is a wasteful number, since it uses less digits than its factorization.

821361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273790.

The product of its digits is 288, while the sum is 21.

The square root of 821361 is about 906.2896887861. The cubic root of 821361 is about 93.6507714543.

Adding to 821361 its reverse (163128), we get a palindrome (984489).

The spelling of 821361 in words is "eight hundred twenty-one thousand, three hundred sixty-one".