16648921 has 8 divisors (see below), whose sum is σ = 17661600. Its totient is φ = 15649920.

The previous prime is 16648909. The next prime is 16648949. The reversal of 16648921 is 12984661.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 16648921 - 2⁵ = 16648889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16648901) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 856 + ... + 5833.

It is an arithmetic number, because the mean of its divisors is an integer number (2207700).

Almost surely, 2^16648921 is an apocalyptic number.

It is an amenable number.

16648921 is a deficient number, since it is larger than the sum of its proper divisors (1012679).

16648921 is a wasteful number, since it uses less digits than its factorization.

16648921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6839.

The product of its digits is 20736, while the sum is 37.

The square root of 16648921 is about 4080.3089343823. The cubic root of 16648921 is about 255.3457874581.

It can be divided in two parts, 1664 and 8921, that added together give a triangular number (10585 = T₁₄₅).

The spelling of 16648921 in words is "sixteen million, six hundred forty-eight thousand, nine hundred twenty-one".