16611661 has 16 divisors (see below), whose sum is σ = 18626688. Its totient is φ = 14688000.

The previous prime is 16611641. The next prime is 16611689.

16611661 is nontrivially palindromic in base 10.

It is a cyclic number.

It is not a de Polignac number, because 16611661 - 2¹¹ = 16609613 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 (16611611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 109936 + ... + 110086.

It is an arithmetic number, because the mean of its divisors is an integer number (1164168).

Almost surely, 2^16611661 is an apocalyptic number.

16611661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16611661 is a deficient number, since it is larger than the sum of its proper divisors (2015027).

16611661 is a wasteful number, since it uses less digits than its factorization.

16611661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 372.

The product of its digits is 1296, while the sum is 28.

The square root of 16611661 is about 4075.7405462075. The cubic root of 16611661 is about 255.1551586799.

The spelling of 16611661 in words is "sixteen million, six hundred eleven thousand, six hundred sixty-one".