16006661 has 4 divisors (see below), whose sum is σ = 17461824. Its totient is φ = 14551500.

The previous prime is 16006657. The next prime is 16006663. The reversal of 16006661 is 16660061.

16006661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16660061 = 11 ⋅1514551.

It is a cyclic number.

It is not a de Polignac number, because 16006661 - 2² = 16006657 is a prime.

It is a super-3 number, since 3×16006661³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 16006661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16006663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 727565 + ... + 727586.

It is an arithmetic number, because the mean of its divisors is an integer number (4365456).

Almost surely, 2^16006661 is an apocalyptic number.

16006661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16006661 is a deficient number, since it is larger than the sum of its proper divisors (1455163).

16006661 is a wasteful number, since it uses less digits than its factorization.

16006661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1455162.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 16006661 is about 4000.8325383600. The cubic root of 16006661 is about 252.0191731864.

The spelling of 16006661 in words is "sixteen million, six thousand, six hundred sixty-one".