16440809729 has 2 divisors, whose sum is σ = 16440809730. Its totient is φ = 16440809728.

The previous prime is 16440809663. The next prime is 16440809779. The reversal of 16440809729 is 92790804461.

It is an a-pointer prime, because the next prime (16440809779) can be obtained adding 16440809729 to its sum of digits (50).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15606755329 + 834054400 = 124927^2 + 28880^2 .

It is a cyclic number.

It is not a de Polignac number, because 16440809729 - 2¹⁶ = 16440744193 is a prime.

It is a super-3 number, since 3×16440809729³ (a number of 32 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (16440809779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8220404864 + 8220404865.

It is an arithmetic number, because the mean of its divisors is an integer number (8220404865).

Almost surely, 2^16440809729 is an apocalyptic number.

It is an amenable number.

16440809729 is a deficient number, since it is larger than the sum of its proper divisors (1).

16440809729 is an equidigital number, since it uses as much as digits as its factorization.

16440809729 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 870912, while the sum is 50.

The spelling of 16440809729 in words is "sixteen billion, four hundred forty million, eight hundred nine thousand, seven hundred twenty-nine".