16906321 has 4 divisors (see below), whose sum is σ = 17064432. Its totient is φ = 16748212.

The previous prime is 16906303. The next prime is 16906339. The reversal of 16906321 is 12360961.

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: 12360961 = 107 ⋅115523.

It is an interprime number because it is at equal distance from previous prime (16906303) and next prime (16906339).

It is a cyclic number.

It is not a de Polignac number, because 16906321 - 2⁷ = 16906193 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16906321.

It is not an unprimeable number, because it can be changed into a prime (16906301) 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, 78895 + ... + 79108.

It is an arithmetic number, because the mean of its divisors is an integer number (4266108).

Almost surely, 2^16906321 is an apocalyptic number.

It is an amenable number.

16906321 is a deficient number, since it is larger than the sum of its proper divisors (158111).

16906321 is a wasteful number, since it uses less digits than its factorization.

16906321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158110.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 16906321 is about 4111.7296846948. The cubic root of 16906321 is about 256.6549847572.

The spelling of 16906321 in words is "sixteen million, nine hundred six thousand, three hundred twenty-one".