1029991209 has 16 divisors (see below), whose sum is σ = 1490614272. Its totient is φ = 628846848.

The previous prime is 1029991199. The next prime is 1029991211. The reversal of 1029991209 is 9021999201.

It is not a de Polignac number, because 1029991209 - 2⁸ = 1029990953 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1029991219) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 99024 + ... + 108929.

It is an arithmetic number, because the mean of its divisors is an integer number (93163392).

Almost surely, 2^1029991209 is an apocalyptic number.

It is an amenable number.

1029991209 is a deficient number, since it is larger than the sum of its proper divisors (460623063).

1029991209 is a wasteful number, since it uses less digits than its factorization.

1029991209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208096.

The product of its (nonzero) digits is 26244, while the sum is 42.

The square root of 1029991209 is about 32093.4761127554. The cubic root of 1029991209 is about 1009.8987608880.

The spelling of 1029991209 in words is "one billion, twenty-nine million, nine hundred ninety-one thousand, two hundred nine".