16388641 has 2 divisors, whose sum is σ = 16388642. Its totient is φ = 16388640.

The previous prime is 16388623. The next prime is 16388681. The reversal of 16388641 is 14688361.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14470416 + 1918225 = 3804^2 + 1385^2 .

It is an emirp because it is prime and its reverse (14688361) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16388641 - 2²³ = 8000033 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16388641.

It is not a weakly prime, because it can be changed into another prime (16388681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8194320 + 8194321.

It is an arithmetic number, because the mean of its divisors is an integer number (8194321).

Almost surely, 2^16388641 is an apocalyptic number.

It is an amenable number.

16388641 is a deficient number, since it is larger than the sum of its proper divisors (1).

16388641 is an equidigital number, since it uses as much as digits as its factorization.

16388641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27648, while the sum is 37.

The square root of 16388641 is about 4048.2886507758. The cubic root of 16388641 is about 254.0081475883.

It can be divided in two parts, 163 and 88641, that added together give a square (88804 = 298²).

The spelling of 16388641 in words is "sixteen million, three hundred eighty-eight thousand, six hundred forty-one".