1019999999 has 8 divisors (see below), whose sum is σ = 1041338592. Its totient is φ = 998739040.

The previous prime is 1019999989. The next prime is 1020000011. The reversal of 1019999999 is 9999999101.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1019999999 is a prime.

It is a Duffinian number.

1019999999 is a modest number, since divided by 99999 gives 10199 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1019999989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7529 + ... + 45789.

It is an arithmetic number, because the mean of its divisors is an integer number (130167324).

Almost surely, 2^1019999999 is an apocalyptic number.

1019999999 is a deficient number, since it is larger than the sum of its proper divisors (21338593).

1019999999 is an equidigital number, since it uses as much as digits as its factorization.

1019999999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38817.

The product of its (nonzero) digits is 4782969, while the sum is 65.

The square root of 1019999999 is about 31937.4388296870. The cubic root of 1019999999 is about 1006.6227092312.

The spelling of 1019999999 in words is "one billion, nineteen million, nine hundred ninety-nine thousand, nine hundred ninety-nine".