209672641 has 2 divisors, whose sum is σ = 209672642. Its totient is φ = 209672640.

The previous prime is 209672633. The next prime is 209672653. The reversal of 209672641 is 146276902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 136399041 + 73273600 = 11679^2 + 8560^2 .

It is a cyclic number.

It is not a de Polignac number, because 209672641 - 2³ = 209672633 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 209672641.

It is not a weakly prime, because it can be changed into another prime (209672741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104836320 + 104836321.

It is an arithmetic number, because the mean of its divisors is an integer number (104836321).

Almost surely, 2^209672641 is an apocalyptic number.

It is an amenable number.

209672641 is a deficient number, since it is larger than the sum of its proper divisors (1).

209672641 is an equidigital number, since it uses as much as digits as its factorization.

209672641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36288, while the sum is 37.

The square root of 209672641 is about 14480.0773823899. The cubic root of 209672641 is about 594.0831780870.

The spelling of 209672641 in words is "two hundred nine million, six hundred seventy-two thousand, six hundred forty-one".