1020099999 has 4 divisors (see below), whose sum is σ = 1360133336. Its totient is φ = 680066664.

The previous prime is 1020099959. The next prime is 1020100001. The reversal of 1020099999 is 9999900201.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1020099999 - 2²¹ = 1018002847 is a prime.

It is a Duffinian number.

1020099999 is a modest number, since divided by 99999 gives 10200 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1020099959) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 170016664 + ... + 170016669.

It is an arithmetic number, because the mean of its divisors is an integer number (340033334).

Almost surely, 2^1020099999 is an apocalyptic number.

1020099999 is a deficient number, since it is larger than the sum of its proper divisors (340033337).

1020099999 is an equidigital number, since it uses as much as digits as its factorization.

1020099999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340033336.

The product of its (nonzero) digits is 118098, while the sum is 48.

The square root of 1020099999 is about 31939.0043520458. The cubic root of 1020099999 is about 1006.6556043232.

The spelling of 1020099999 in words is "one billion, twenty million, ninety-nine thousand, nine hundred ninety-nine".