16721330 has 16 divisors (see below), whose sum is σ = 31682880. Its totient is φ = 6336432.

The previous prime is 16721297. The next prime is 16721333. The reversal of 16721330 is 3312761.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 16721296 and 16721305.

It is not an unprimeable number, because it can be changed into a prime (16721333) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43814 + ... + 44193.

It is an arithmetic number, because the mean of its divisors is an integer number (1980180).

Almost surely, 2^16721330 is an apocalyptic number.

16721330 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

16721330 is a deficient number, since it is larger than the sum of its proper divisors (14961550).

16721330 is a wasteful number, since it uses less digits than its factorization.

16721330 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88033.

The product of its (nonzero) digits is 756, while the sum is 23.

The square root of 16721330 is about 4089.1722878842. The cubic root of 16721330 is about 255.7154329000.

The spelling of 16721330 in words is "sixteen million, seven hundred twenty-one thousand, three hundred thirty".