16600000991 has 16 divisors (see below), whose sum is σ = 19312366080. Its totient is φ = 13973355360.

The previous prime is 16600000987. The next prime is 16600001009. The reversal of 16600000991 is 19900000661.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 16600000991 - 2² = 16600000987 is a prime.

16600000991 is a strobogrammatic number because it is the same when read upside-down.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16600000891) 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, 401990 + ... + 441356.

It is an arithmetic number, because the mean of its divisors is an integer number (1207022880).

Almost surely, 2^16600000991 is an apocalyptic number.

16600000991 is a deficient number, since it is larger than the sum of its proper divisors (2712365089).

16600000991 is a wasteful number, since it uses less digits than its factorization.

16600000991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40454.

The product of its (nonzero) digits is 2916, while the sum is 32.

The spelling of 16600000991 in words is "sixteen billion, six hundred million, nine hundred ninety-one", and thus it is an aban number.