19909823810 has 16 divisors (see below), whose sum is σ = 35874381816. Its totient is φ = 7955774208.

The previous prime is 19909823777. The next prime is 19909823827. The reversal of 19909823810 is 1832890991.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 17931620281 + 1978203529 = 133909^2 + 44477^2 .

It is a super-2 number, since 2×19909823810² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1009157 + ... + 1028696.

Almost surely, 2^19909823810 is an apocalyptic number.

19909823810 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19909823810 is a deficient number, since it is larger than the sum of its proper divisors (15964558006).

19909823810 is a wasteful number, since it uses less digits than its factorization.

19909823810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2038837.

The product of its (nonzero) digits is 279936, while the sum is 50.

The spelling of 19909823810 in words is "nineteen billion, nine hundred nine million, eight hundred twenty-three thousand, eight hundred ten".