690218369 has 2 divisors, whose sum is σ = 690218370. Its totient is φ = 690218368.

The previous prime is 690218329. The next prime is 690218381. The reversal of 690218369 is 963812096.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 683142769 + 7075600 = 26137^2 + 2660^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-690218369 is a prime.

It is a super-2 number, since 2×690218369² = 952802793810040322, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (690218329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345109184 + 345109185.

It is an arithmetic number, because the mean of its divisors is an integer number (345109185).

Almost surely, 2^690218369 is an apocalyptic number.

It is an amenable number.

690218369 is a deficient number, since it is larger than the sum of its proper divisors (1).

690218369 is an equidigital number, since it uses as much as digits as its factorization.

690218369 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 139968, while the sum is 44.

The square root of 690218369 is about 26272.0073271914. The cubic root of 690218369 is about 883.7488012430.

The spelling of 690218369 in words is "six hundred ninety million, two hundred eighteen thousand, three hundred sixty-nine".