16444021 has 12 divisors (see below), whose sum is σ = 18568396. Its totient is φ = 14541120.

The previous prime is 16444019. The next prime is 16444033. The reversal of 16444021 is 12044461.

It can be written as a sum of positive squares in 2 ways, for example, as 7623121 + 8820900 = 2761^2 + 2970^2 .

It is not a de Polignac number, because 16444021 - 2¹ = 16444019 is a prime.

It is a super-3 number, since 3×16444021³ (a number of 23 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 16443983 and 16444001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16444091) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2641 + ... + 6313.

Almost surely, 2^16444021 is an apocalyptic number.

16444021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16444021 is a deficient number, since it is larger than the sum of its proper divisors (2124375).

16444021 is a wasteful number, since it uses less digits than its factorization.

16444021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3732 (or 3721 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 16444021 is about 4055.1228094843. The cubic root of 16444021 is about 254.2939381347.

Adding to 16444021 its reverse (12044461), we get a palindrome (28488482).

It can be divided in two parts, 164440 and 21, that added together give a palindrome (164461).

The spelling of 16444021 in words is "sixteen million, four hundred forty-four thousand, twenty-one".