16121649 has 4 divisors (see below), whose sum is σ = 21495536. Its totient is φ = 10747764.

The previous prime is 16121647. The next prime is 16121657. The reversal of 16121649 is 94612161.

It is a happy number.

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 not a de Polignac number, because 16121649 - 2¹ = 16121647 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16121647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2686939 + ... + 2686944.

It is an arithmetic number, because the mean of its divisors is an integer number (5373884).

Almost surely, 2^16121649 is an apocalyptic number.

It is an amenable number.

16121649 is a deficient number, since it is larger than the sum of its proper divisors (5373887).

16121649 is an equidigital number, since it uses as much as digits as its factorization.

16121649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5373886.

The product of its digits is 2592, while the sum is 30.

The square root of 16121649 is about 4015.1773310777. The cubic root of 16121649 is about 252.6212155311.

The spelling of 16121649 in words is "sixteen million, one hundred twenty-one thousand, six hundred forty-nine".