16491539 has 4 divisors (see below), whose sum is σ = 16519056. Its totient is φ = 16464024.

The previous prime is 16491523. The next prime is 16491551. The reversal of 16491539 is 93519461.

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 16491539 - 2⁴ = 16491523 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16491509) 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, 12839 + ... + 14064.

It is an arithmetic number, because the mean of its divisors is an integer number (4129764).

Almost surely, 2^16491539 is an apocalyptic number.

16491539 is a deficient number, since it is larger than the sum of its proper divisors (27517).

16491539 is an equidigital number, since it uses as much as digits as its factorization.

16491539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27516.

The product of its digits is 29160, while the sum is 38.

The square root of 16491539 is about 4060.9775916644. The cubic root of 16491539 is about 254.5386454927.

The spelling of 16491539 in words is "sixteen million, four hundred ninety-one thousand, five hundred thirty-nine".