16990561 has 8 divisors (see below), whose sum is σ = 19479104. Its totient is φ = 14517360.

The previous prime is 16990559. The next prime is 16990577. The reversal of 16990561 is 16509961.

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 16990561 - 2¹ = 16990559 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16990561.

It is not an unprimeable number, because it can be changed into a prime (16990591) 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, 1350 + ... + 5983.

It is an arithmetic number, because the mean of its divisors is an integer number (2434888).

Almost surely, 2^16990561 is an apocalyptic number.

It is an amenable number.

16990561 is a deficient number, since it is larger than the sum of its proper divisors (2488543).

16990561 is an equidigital number, since it uses as much as digits as its factorization.

16990561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7671.

The product of its (nonzero) digits is 14580, while the sum is 37.

The square root of 16990561 is about 4121.9608198041. The cubic root of 16990561 is about 257.0805613791.

The spelling of 16990561 in words is "sixteen million, nine hundred ninety thousand, five hundred sixty-one".