209149471 has 2 divisors, whose sum is σ = 209149472. Its totient is φ = 209149470.

The previous prime is 209149441. The next prime is 209149481. The reversal of 209149471 is 174941902.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 209149471 - 2⁵ = 209149439 is a prime.

It is a super-3 number, since 3×209149471³ (a number of 26 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 209149471.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (209149441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104574735 + 104574736.

It is an arithmetic number, because the mean of its divisors is an integer number (104574736).

Almost surely, 2^209149471 is an apocalyptic number.

209149471 is a deficient number, since it is larger than the sum of its proper divisors (1).

209149471 is an equidigital number, since it uses as much as digits as its factorization.

209149471 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18144, while the sum is 37.

The square root of 209149471 is about 14462.0009334808. Note that the first 3 decimals coincide. The cubic root of 209149471 is about 593.5886526539.

The spelling of 209149471 in words is "two hundred nine million, one hundred forty-nine thousand, four hundred seventy-one".