16423661 has 4 divisors (see below), whose sum is σ = 16432800. Its totient is φ = 16414524.

The previous prime is 16423637. The next prime is 16423663. The reversal of 16423661 is 16632461.

It is a happy number.

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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 16632461 = 31 ⋅536531.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16423661 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16423663) 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, 881 + ... + 5798.

It is an arithmetic number, because the mean of its divisors is an integer number (4108200).

Almost surely, 2^16423661 is an apocalyptic number.

It is an amenable number.

16423661 is a deficient number, since it is larger than the sum of its proper divisors (9139).

16423661 is an equidigital number, since it uses as much as digits as its factorization.

16423661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9138.

The product of its digits is 5184, while the sum is 29.

The square root of 16423661 is about 4052.6116270869. The cubic root of 16423661 is about 254.1889442924.

The spelling of 16423661 in words is "sixteen million, four hundred twenty-three thousand, six hundred sixty-one".