99991706 has 4 divisors (see below), whose sum is σ = 149987562. Its totient is φ = 49995852.

The previous prime is 99991687. The next prime is 99991721. The reversal of 99991706 is 60719999.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 60719999 = 43 ⋅1412093.

It can be written as a sum of positive squares in only one way, i.e., 93915481 + 6076225 = 9691^2 + 2465^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 24997925 + ... + 24997928.

Almost surely, 2^99991706 is an apocalyptic number.

99991706 is a deficient number, since it is larger than the sum of its proper divisors (49995856).

99991706 is a wasteful number, since it uses less digits than its factorization.

99991706 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49995855.

The product of its (nonzero) digits is 275562, while the sum is 50.

The square root of 99991706 is about 9999.5852914008. The cubic root of 99991706 is about 464.1460505606.

The spelling of 99991706 in words is "ninety-nine million, nine hundred ninety-one thousand, seven hundred six".