209144979 has 12 divisors (see below), whose sum is σ = 310263616. Its totient is φ = 135661392.

The previous prime is 209144939. The next prime is 209144981. The reversal of 209144979 is 979441902.

It is a happy number.

It is not a de Polignac number, because 209144979 - 2¹⁹ = 208620691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (209144909) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 313699 + ... + 314364.

Almost surely, 2^209144979 is an apocalyptic number.

209144979 is a deficient number, since it is larger than the sum of its proper divisors (101118637).

209144979 is a wasteful number, since it uses less digits than its factorization.

209144979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 628106 (or 628103 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 45.

The square root of 209144979 is about 14461.8456291028. The cubic root of 209144979 is about 593.5844030307.

The spelling of 209144979 in words is "two hundred nine million, one hundred forty-four thousand, nine hundred seventy-nine".