99991606 has 32 divisors (see below), whose sum is σ = 176930208. Its totient is φ = 41783040.

The previous prime is 99991583. The next prime is 99991609. The reversal of 99991606 is 60619999.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 99991606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99991609) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 88960 + ... + 90076.

It is an arithmetic number, because the mean of its divisors is an integer number (5529069).

Almost surely, 2^99991606 is an apocalyptic number.

99991606 is a deficient number, since it is larger than the sum of its proper divisors (76938602).

99991606 is a wasteful number, since it uses less digits than its factorization.

99991606 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1456.

The product of its (nonzero) digits is 236196, while the sum is 49.

The square root of 99991606 is about 9999.5802911922. The cubic root of 99991606 is about 464.1458958323.

The spelling of 99991606 in words is "ninety-nine million, nine hundred ninety-one thousand, six hundred six".