209979041 has 2 divisors, whose sum is σ = 209979042. Its totient is φ = 209979040.

The previous prime is 209978987. The next prime is 209979061. The reversal of 209979041 is 140979902.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 115111441 + 94867600 = 10729^2 + 9740^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-209979041 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 209979041.

It is not a weakly prime, because it can be changed into another prime (209979061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104989520 + 104989521.

It is an arithmetic number, because the mean of its divisors is an integer number (104989521).

Almost surely, 2^209979041 is an apocalyptic number.

It is an amenable number.

209979041 is a deficient number, since it is larger than the sum of its proper divisors (1).

209979041 is an equidigital number, since it uses as much as digits as its factorization.

209979041 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40824, while the sum is 41.

The square root of 209979041 is about 14490.6535739421. The cubic root of 209979041 is about 594.3724202279.

The spelling of 209979041 in words is "two hundred nine million, nine hundred seventy-nine thousand, forty-one".