821497 has 2 divisors, whose sum is σ = 821498. Its totient is φ = 821496.

The previous prime is 821489. The next prime is 821507. The reversal of 821497 is 794128.

821497 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 674041 + 147456 = 821^2 + 384^2 .

It is a cyclic number.

It is not a de Polignac number, because 821497 - 2³ = 821489 is a prime.

It is not a weakly prime, because it can be changed into another prime (821467) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410748 + 410749.

It is an arithmetic number, because the mean of its divisors is an integer number (410749).

2⁸²¹⁴⁹⁷ is an apocalyptic number.

It is an amenable number.

821497 is a deficient number, since it is larger than the sum of its proper divisors (1).

821497 is an equidigital number, since it uses as much as digits as its factorization.

821497 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4032, while the sum is 31.

The square root of 821497 is about 906.3647168773. The cubic root of 821497 is about 93.6559400310.

The spelling of 821497 in words is "eight hundred twenty-one thousand, four hundred ninety-seven".