99991506 has 8 divisors (see below), whose sum is σ = 199983024. Its totient is φ = 33330500.

The previous prime is 99991499. The next prime is 99991517. The reversal of 99991506 is 60519999.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

99991506 is an admirable number.

It is a Curzon number.

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 in 3 ways as a sum of consecutive naturals, for example, 8332620 + ... + 8332631.

It is an arithmetic number, because the mean of its divisors is an integer number (24997878).

Almost surely, 2^99991506 is an apocalyptic number.

99991506 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

99991506 is a wasteful number, since it uses less digits than its factorization.

99991506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16665256.

The product of its (nonzero) digits is 196830, while the sum is 48.

The square root of 99991506 is about 9999.5752909811. The cubic root of 99991506 is about 464.1457411040.

The spelling of 99991506 in words is "ninety-nine million, nine hundred ninety-one thousand, five hundred six".