16015661 has 4 divisors (see below), whose sum is σ = 16044672. Its totient is φ = 15986652.

The previous prime is 16015619. The next prime is 16015669. The reversal of 16015661 is 16651061.

16015661 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.

It is a cyclic number.

It is not a de Polignac number, because 16015661 - 2¹⁰ = 16014637 is a prime.

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 16015661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16015669) 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, 13661 + ... + 14786.

It is an arithmetic number, because the mean of its divisors is an integer number (4011168).

Almost surely, 2^16015661 is an apocalyptic number.

It is an amenable number.

16015661 is a deficient number, since it is larger than the sum of its proper divisors (29011).

16015661 is an equidigital number, since it uses as much as digits as its factorization.

16015661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29010.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 16015661 is about 4001.9571461973. The cubic root of 16015661 is about 252.0663982673.

The spelling of 16015661 in words is "sixteen million, fifteen thousand, six hundred sixty-one".