16645649 has 2 divisors, whose sum is σ = 16645650. Its totient is φ = 16645648.

The previous prime is 16645639. The next prime is 16645663. The reversal of 16645649 is 94654661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12673600 + 3972049 = 3560^2 + 1993^2 .

It is a cyclic number.

It is not a de Polignac number, because 16645649 - 2¹² = 16641553 is a prime.

It is not a weakly prime, because it can be changed into another prime (16645639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8322824 + 8322825.

It is an arithmetic number, because the mean of its divisors is an integer number (8322825).

Almost surely, 2^16645649 is an apocalyptic number.

It is an amenable number.

16645649 is a deficient number, since it is larger than the sum of its proper divisors (1).

16645649 is an equidigital number, since it uses as much as digits as its factorization.

16645649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 155520, while the sum is 41.

The square root of 16645649 is about 4079.9079646482. The cubic root of 16645649 is about 255.3290587233.

The spelling of 16645649 in words is "sixteen million, six hundred forty-five thousand, six hundred forty-nine".