16721245738 has 16 divisors (see below), whose sum is σ = 25314001416. Its totient is φ = 8283304960.

The previous prime is 16721245711. The next prime is 16721245787. The reversal of 16721245738 is 83754212761.

It can be written as a sum of positive squares in 4 ways, for example, as 3321562689 + 13399683049 = 57633^2 + 115757^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 605970 + ... + 632962.

Almost surely, 2^16721245738 is an apocalyptic number.

16721245738 is a deficient number, since it is larger than the sum of its proper divisors (8592755678).

16721245738 is a wasteful number, since it uses less digits than its factorization.

16721245738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29849.

The product of its digits is 564480, while the sum is 46.

It can be divided in two parts, 1672 and 1245738, that added together give a triangular number (1247410 = T₁₅₇₉).

The spelling of 16721245738 in words is "sixteen billion, seven hundred twenty-one million, two hundred forty-five thousand, seven hundred thirty-eight".