16651649 has 4 divisors (see below), whose sum is σ = 19030464. Its totient is φ = 14272836.

The previous prime is 16651639. The next prime is 16651667. The reversal of 16651649 is 94615661.

16651649 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16651649 - 2¹⁶ = 16586113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16651639) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1189397 + ... + 1189410.

It is an arithmetic number, because the mean of its divisors is an integer number (4757616).

Almost surely, 2^16651649 is an apocalyptic number.

It is an amenable number.

16651649 is a deficient number, since it is larger than the sum of its proper divisors (2378815).

16651649 is an equidigital number, since it uses as much as digits as its factorization.

16651649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2378814.

The product of its digits is 38880, while the sum is 38.

The square root of 16651649 is about 4080.6432091032. The cubic root of 16651649 is about 255.3597332120.

It can be divided in two parts, 166 and 51649, that added together give a palindrome (51815).

The spelling of 16651649 in words is "sixteen million, six hundred fifty-one thousand, six hundred forty-nine".