999979999906 has 4 divisors (see below), whose sum is σ = 1499969999862. Its totient is φ = 499989999952.

The previous prime is 999979999873. The next prime is 999979999951. The reversal of 999979999906 is 609999979999.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 609999979999 = 47659 ⋅12799261.

It can be written as a sum of positive squares in only one way, i.e., 689888054025 + 310091945881 = 830595^2 + 556859^2 .

It is a Smith number, since the sum of its digits (94) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 249994999975 + ... + 249994999978.

Almost surely, 2^999979999906 is an apocalyptic number.

999979999906 is a deficient number, since it is larger than the sum of its proper divisors (499989999956).

999979999906 is a wasteful number, since it uses less digits than its factorization.

999979999906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 499989999955.

The product of its (nonzero) digits is 16271660538, while the sum is 94.

The spelling of 999979999906 in words is "nine hundred ninety-nine billion, nine hundred seventy-nine million, nine hundred ninety-nine thousand, nine hundred six".