1999189856 has 12 divisors (see below), whose sum is σ = 3935905092. Its totient is φ = 999594912.

The previous prime is 1999189853. The next prime is 1999189891. The reversal of 1999189856 is 6589819991.

It is a junction number, because it is equal to n+sod(n) for n = 1999189792 and 1999189801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1999189853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31237310 + ... + 31237373.

It is an arithmetic number, because the mean of its divisors is an integer number (327992091).

Almost surely, 2^1999189856 is an apocalyptic number.

1999189856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1999189856 is a deficient number, since it is larger than the sum of its proper divisors (1936715236).

1999189856 is an equidigital number, since it uses as much as digits as its factorization.

1999189856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62474693 (or 62474685 counting only the distinct ones).

The product of its digits is 12597120, while the sum is 65.

The square root of 1999189856 is about 44712.3009472785. The cubic root of 1999189856 is about 1259.7509073396.

The spelling of 1999189856 in words is "one billion, nine hundred ninety-nine million, one hundred eighty-nine thousand, eight hundred fifty-six".