209979145469 has 2 divisors, whose sum is σ = 209979145470. Its totient is φ = 209979145468.

The previous prime is 209979145433. The next prime is 209979145489. The reversal of 209979145469 is 964541979902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 127013832100 + 82965313369 = 356390^2 + 288037^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-209979145469 is a prime.

It is a super-2 number, since 2×209979145469² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (209979145489) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104989572734 + 104989572735.

It is an arithmetic number, because the mean of its divisors is an integer number (104989572735).

Almost surely, 2^209979145469 is an apocalyptic number.

It is an amenable number.

209979145469 is a deficient number, since it is larger than the sum of its proper divisors (1).

209979145469 is an equidigital number, since it uses as much as digits as its factorization.

209979145469 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 44089920, while the sum is 65.

The spelling of 209979145469 in words is "two hundred nine billion, nine hundred seventy-nine million, one hundred forty-five thousand, four hundred sixty-nine".