16921447 has 2 divisors, whose sum is σ = 16921448. Its totient is φ = 16921446.

The previous prime is 16921427. The next prime is 16921493. The reversal of 16921447 is 74412961.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16921447 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16921427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8460723 + 8460724.

It is an arithmetic number, because the mean of its divisors is an integer number (8460724).

Almost surely, 2^16921447 is an apocalyptic number.

16921447 is a deficient number, since it is larger than the sum of its proper divisors (1).

16921447 is an equidigital number, since it uses as much as digits as its factorization.

16921447 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 34.

The square root of 16921447 is about 4113.5686453492. The cubic root of 16921447 is about 256.7315045806.

The spelling of 16921447 in words is "sixteen million, nine hundred twenty-one thousand, four hundred forty-seven".