1999904506 has 4 divisors (see below), whose sum is σ = 2999856762. Its totient is φ = 999952252.

The previous prime is 1999904479. The next prime is 1999904521. The reversal of 1999904506 is 6054099991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6054099991 = 523 ⋅11575717.

It can be written as a sum of positive squares in only one way, i.e., 1002292281 + 997612225 = 31659^2 + 31585^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499976125 + ... + 499976128.

Almost surely, 2^1999904506 is an apocalyptic number.

1999904506 is a deficient number, since it is larger than the sum of its proper divisors (999952256).

1999904506 is an equidigital number, since it uses as much as digits as its factorization.

1999904506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 999952255.

The product of its (nonzero) digits is 787320, while the sum is 52.

The square root of 1999904506 is about 44720.2918818739. The cubic root of 1999904506 is about 1259.9009970923.

The spelling of 1999904506 in words is "one billion, nine hundred ninety-nine million, nine hundred four thousand, five hundred six".