16451891 has 4 divisors (see below), whose sum is σ = 17317800. Its totient is φ = 15585984.

The previous prime is 16451867. The next prime is 16451921. The reversal of 16451891 is 19815461.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 16451891 - 2¹⁰ = 16450867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16451191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 432926 + ... + 432963.

It is an arithmetic number, because the mean of its divisors is an integer number (4329450).

Almost surely, 2^16451891 is an apocalyptic number.

16451891 is a deficient number, since it is larger than the sum of its proper divisors (865909).

16451891 is an equidigital number, since it uses as much as digits as its factorization.

16451891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 865908.

The product of its digits is 8640, while the sum is 35.

The square root of 16451891 is about 4056.0930709243. The cubic root of 16451891 is about 254.3344994651.

The spelling of 16451891 in words is "sixteen million, four hundred fifty-one thousand, eight hundred ninety-one".