16519997 has 8 divisors (see below), whose sum is σ = 17840760. Its totient is φ = 15206400.

The previous prime is 16519991. The next prime is 16519999. The reversal of 16519997 is 79991561.

It can be written as a sum of positive squares in 4 ways, for example, as 7150276 + 9369721 = 2674^2 + 3061^2 .

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 16519997 - 2¹⁰ = 16518973 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 (16519991) 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, 3629 + ... + 6797.

It is an arithmetic number, because the mean of its divisors is an integer number (2230095).

Almost surely, 2^16519997 is an apocalyptic number.

It is an amenable number.

16519997 is a deficient number, since it is larger than the sum of its proper divisors (1320763).

16519997 is a wasteful number, since it uses less digits than its factorization.

16519997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3583.

The product of its digits is 153090, while the sum is 47.

The square root of 16519997 is about 4064.4799175294. The cubic root of 16519997 is about 254.6849730162.

The spelling of 16519997 in words is "sixteen million, five hundred nineteen thousand, nine hundred ninety-seven".