16607991 has 8 divisors (see below), whose sum is σ = 22184064. Its totient is φ = 11051960.

The previous prime is 16607989. The next prime is 16607999. The reversal of 16607991 is 19970661.

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

It is a cyclic number.

It is not a de Polignac number, because 16607991 - 2¹ = 16607989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16607999) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2955 + ... + 6476.

It is an arithmetic number, because the mean of its divisors is an integer number (2773008).

Almost surely, 2^16607991 is an apocalyptic number.

16607991 is a deficient number, since it is larger than the sum of its proper divisors (5576073).

16607991 is an equidigital number, since it uses as much as digits as its factorization.

16607991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10021.

The product of its (nonzero) digits is 20412, while the sum is 39.

The square root of 16607991 is about 4075.2902964083. The cubic root of 16607991 is about 255.1363668926.

The spelling of 16607991 in words is "sixteen million, six hundred seven thousand, nine hundred ninety-one".