16921441 has 4 divisors (see below), whose sum is σ = 16942000. Its totient is φ = 16900884.

The previous prime is 16921427. The next prime is 16921447. The reversal of 16921441 is 14412961.

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: 14412961 = 109 ⋅132229.

It is a cyclic number.

It is not a de Polignac number, because 16921441 - 2¹⁷ = 16790369 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16921447) 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, 8991 + ... + 10708.

It is an arithmetic number, because the mean of its divisors is an integer number (4235500).

Almost surely, 2^16921441 is an apocalyptic number.

It is an amenable number.

16921441 is a deficient number, since it is larger than the sum of its proper divisors (20559).

16921441 is an equidigital number, since it uses as much as digits as its factorization.

16921441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20558.

The product of its digits is 1728, while the sum is 28.

The square root of 16921441 is about 4113.5679160554. The cubic root of 16921441 is about 256.7314742367.

The spelling of 16921441 in words is "sixteen million, nine hundred twenty-one thousand, four hundred forty-one".