16626991 has 8 divisors (see below), whose sum is σ = 16943040. Its totient is φ = 16313472.

The previous prime is 16626989. The next prime is 16627057. The reversal of 16626991 is 19962661.

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 16626991 - 2¹ = 16626989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16626941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16971 + ... + 17923.

It is an arithmetic number, because the mean of its divisors is an integer number (2117880).

Almost surely, 2^16626991 is an apocalyptic number.

16626991 is a deficient number, since it is larger than the sum of its proper divisors (316049).

16626991 is an equidigital number, since it uses as much as digits as its factorization.

16626991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1265.

The product of its digits is 34992, while the sum is 40.

The square root of 16626991 is about 4077.6207523506. The cubic root of 16626991 is about 255.2336241618.

The spelling of 16626991 in words is "sixteen million, six hundred twenty-six thousand, nine hundred ninety-one".