821965 has 8 divisors (see below), whose sum is σ = 1018368. Its totient is φ = 636240.

The previous prime is 821941. The next prime is 821971. The reversal of 821965 is 569128.

821965 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 a de Polignac number, because none of the positive numbers 2^k-821965 is a prime.

It is a super-2 number, since 2×821965² = 1351252922450, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2497 + ... + 2806.

It is an arithmetic number, because the mean of its divisors is an integer number (127296).

2⁸²¹⁹⁶⁵ is an apocalyptic number.

It is an amenable number.

821965 is a deficient number, since it is larger than the sum of its proper divisors (196403).

821965 is a wasteful number, since it uses less digits than its factorization.

821965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5339.

The product of its digits is 4320, while the sum is 31.

The square root of 821965 is about 906.6228543336. The cubic root of 821965 is about 93.6737216578.

The spelling of 821965 in words is "eight hundred twenty-one thousand, nine hundred sixty-five".