16438821 has 16 divisors (see below), whose sum is σ = 25110144. Its totient is φ = 9370944.

The previous prime is 16438817. The next prime is 16438831. The reversal of 16438821 is 12883461.

It is not a de Polignac number, because 16438821 - 2² = 16438817 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16438831) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12235 + ... + 13511.

It is an arithmetic number, because the mean of its divisors is an integer number (1569384).

Almost surely, 2^16438821 is an apocalyptic number.

It is an amenable number.

16438821 is a deficient number, since it is larger than the sum of its proper divisors (8671323).

16438821 is a wasteful number, since it uses less digits than its factorization.

16438821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1900.

The product of its digits is 9216, while the sum is 33.

The square root of 16438821 is about 4054.4815944828. The cubic root of 16438821 is about 254.2671306629.

The spelling of 16438821 in words is "sixteen million, four hundred thirty-eight thousand, eight hundred twenty-one".