16766561 has 8 divisors (see below), whose sum is σ = 19487040. Its totient is φ = 14127408.

The previous prime is 16766557. The next prime is 16766593. The reversal of 16766561 is 16566761.

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 16766561 - 2² = 16766557 is a prime.

It is a super-2 number, since 2×16766561² = 562235135533442, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (16766551) 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, 19886 + ... + 20711.

It is an arithmetic number, because the mean of its divisors is an integer number (2435880).

Almost surely, 2^16766561 is an apocalyptic number.

It is an amenable number.

16766561 is a deficient number, since it is larger than the sum of its proper divisors (2720479).

16766561 is an equidigital number, since it uses as much as digits as its factorization.

16766561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40663.

The product of its digits is 45360, while the sum is 38.

The square root of 16766561 is about 4094.6991342466. The cubic root of 16766561 is about 255.9457943908.

The spelling of 16766561 in words is "sixteen million, seven hundred sixty-six thousand, five hundred sixty-one".