1999123005 has 32 divisors (see below), whose sum is σ = 3491486208. Its totient is φ = 968686400.

The previous prime is 1999123001. The next prime is 1999123067. The reversal of 1999123005 is 5003219991.

It is not a de Polignac number, because 1999123005 - 2² = 1999123001 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1999123001) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 415222 + ... + 420008.

It is an arithmetic number, because the mean of its divisors is an integer number (109108944).

Almost surely, 2^1999123005 is an apocalyptic number.

1999123005 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1999123005 is a deficient number, since it is larger than the sum of its proper divisors (1492363203).

1999123005 is a wasteful number, since it uses less digits than its factorization.

1999123005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7337.

The product of its (nonzero) digits is 21870, while the sum is 39.

The square root of 1999123005 is about 44711.5533727022. The cubic root of 1999123005 is about 1259.7368655606.

The spelling of 1999123005 in words is "one billion, nine hundred ninety-nine million, one hundred twenty-three thousand, five".