698445821 has 2 divisors, whose sum is σ = 698445822. Its totient is φ = 698445820.

The previous prime is 698445739. The next prime is 698445829. The reversal of 698445821 is 128544896.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 628053721 + 70392100 = 25061^2 + 8390^2 .

It is a cyclic number.

It is not a de Polignac number, because 698445821 - 2¹⁰ = 698444797 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (698445829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 349222910 + 349222911.

It is an arithmetic number, because the mean of its divisors is an integer number (349222911).

Almost surely, 2^698445821 is an apocalyptic number.

It is an amenable number.

698445821 is a deficient number, since it is larger than the sum of its proper divisors (1).

698445821 is an equidigital number, since it uses as much as digits as its factorization.

698445821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 552960, while the sum is 47.

The square root of 698445821 is about 26428.1255672815. The cubic root of 698445821 is about 887.2463901691.

The spelling of 698445821 in words is "six hundred ninety-eight million, four hundred forty-five thousand, eight hundred twenty-one".