16643949 has 16 divisors (see below), whose sum is σ = 25480320. Its totient is φ = 9466560.

The previous prime is 16643947. The next prime is 16643971. The reversal of 16643949 is 94934661.

It is not a de Polignac number, because 16643949 - 2¹ = 16643947 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16643949.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16643947) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 3079 + ... + 6539.

It is an arithmetic number, because the mean of its divisors is an integer number (1592520).

Almost surely, 2^16643949 is an apocalyptic number.

It is an amenable number.

16643949 is a deficient number, since it is larger than the sum of its proper divisors (8836371).

16643949 is a wasteful number, since it uses less digits than its factorization.

16643949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3700.

The product of its digits is 139968, while the sum is 42.

The square root of 16643949 is about 4079.6996212957. The cubic root of 16643949 is about 255.3203662780.

The spelling of 16643949 in words is "sixteen million, six hundred forty-three thousand, nine hundred forty-nine".