957821 has 2 divisors, whose sum is σ = 957822. Its totient is φ = 957820.

The previous prime is 957811. The next prime is 957823. The reversal of 957821 is 128759.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 912025 + 45796 = 955^2 + 214^2 .

It is a cyclic number.

It is not a de Polignac number, because 957821 - 2¹⁸ = 695677 is a prime.

Together with 957823, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (957823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 478910 + 478911.

It is an arithmetic number, because the mean of its divisors is an integer number (478911).

2⁹⁵⁷⁸²¹ is an apocalyptic number.

It is an amenable number.

957821 is a deficient number, since it is larger than the sum of its proper divisors (1).

957821 is an equidigital number, since it uses as much as digits as its factorization.

957821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5040, while the sum is 32.

The square root of 957821 is about 978.6832991321. The cubic root of 957821 is about 98.5737892634.

The spelling of 957821 in words is "nine hundred fifty-seven thousand, eight hundred twenty-one".