16505661 has 8 divisors (see below), whose sum is σ = 23165920. Its totient is φ = 10424592.

The previous prime is 16505653. The next prime is 16505677. The reversal of 16505661 is 16650561.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 16505661 - 2³ = 16505653 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 (16505641) 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, 144730 + ... + 144843.

It is an arithmetic number, because the mean of its divisors is an integer number (2895740).

Almost surely, 2^16505661 is an apocalyptic number.

It is an amenable number.

16505661 is a deficient number, since it is larger than the sum of its proper divisors (6660259).

16505661 is a wasteful number, since it uses less digits than its factorization.

16505661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289595.

The product of its (nonzero) digits is 5400, while the sum is 30.

The square root of 16505661 is about 4062.7159634904. The cubic root of 16505661 is about 254.6112800965.

The spelling of 16505661 in words is "sixteen million, five hundred five thousand, six hundred sixty-one".