698821 has 2 divisors, whose sum is σ = 698822. Its totient is φ = 698820.

The previous prime is 698779. The next prime is 698827. The reversal of 698821 is 128896.

698821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 664225 + 34596 = 815^2 + 186^2 .

It is a cyclic number.

It is not a de Polignac number, because 698821 - 2¹³ = 690629 is a prime.

698821 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (698827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 349410 + 349411.

It is an arithmetic number, because the mean of its divisors is an integer number (349411).

2⁶⁹⁸⁸²¹ is an apocalyptic number.

It is an amenable number.

698821 is a deficient number, since it is larger than the sum of its proper divisors (1).

698821 is an equidigital number, since it uses as much as digits as its factorization.

698821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6912, while the sum is 34.

The square root of 698821 is about 835.9551423372. The cubic root of 698821 is about 88.7405226936.

The spelling of 698821 in words is "six hundred ninety-eight thousand, eight hundred twenty-one".