16540017649 has 2 divisors, whose sum is σ = 16540017650. Its totient is φ = 16540017648.

The previous prime is 16540017647. The next prime is 16540017671. The reversal of 16540017649 is 94671004561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16414734400 + 125283249 = 128120^2 + 11193^2 .

It is a cyclic number.

It is not a de Polignac number, because 16540017649 - 2¹ = 16540017647 is a prime.

Together with 16540017647, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (16540017647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8270008824 + 8270008825.

It is an arithmetic number, because the mean of its divisors is an integer number (8270008825).

Almost surely, 2^16540017649 is an apocalyptic number.

It is an amenable number.

16540017649 is a deficient number, since it is larger than the sum of its proper divisors (1).

16540017649 is an equidigital number, since it uses as much as digits as its factorization.

16540017649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 181440, while the sum is 43.

The spelling of 16540017649 in words is "sixteen billion, five hundred forty million, seventeen thousand, six hundred forty-nine".