16721047 has 16 divisors (see below), whose sum is σ = 20355840. Its totient is φ = 13408128.

The previous prime is 16721041. The next prime is 16721051. The reversal of 16721047 is 74012761.

It is a cyclic number.

It is not a de Polignac number, because 16721047 - 2³ = 16721039 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16721041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26704 + ... + 27322.

It is an arithmetic number, because the mean of its divisors is an integer number (1272240).

Almost surely, 2^16721047 is an apocalyptic number.

16721047 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

16721047 is a deficient number, since it is larger than the sum of its proper divisors (3634793).

16721047 is a wasteful number, since it uses less digits than its factorization.

16721047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 870.

The product of its (nonzero) digits is 2352, while the sum is 28.

The square root of 16721047 is about 4089.1376841579. The cubic root of 16721047 is about 255.7139902740.

The spelling of 16721047 in words is "sixteen million, seven hundred twenty-one thousand, forty-seven".