21035444 has 12 divisors (see below), whose sum is σ = 36966468. Its totient is φ = 10473600.

The previous prime is 21035431. The next prime is 21035449. The reversal of 21035444 is 44453012.

It can be written as a sum of positive squares in 2 ways, for example, as 14212900 + 6822544 = 3770^2 + 2612^2 .

It is a hoax number, since the sum of its digits (23) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21035449) 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, 9947 + ... + 11874.

It is an arithmetic number, because the mean of its divisors is an integer number (3080539).

Almost surely, 2^21035444 is an apocalyptic number.

It is an amenable number.

21035444 is a deficient number, since it is larger than the sum of its proper divisors (15931024).

21035444 is a wasteful number, since it uses less digits than its factorization.

21035444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22066 (or 22064 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 21035444 is about 4586.4413219837. The cubic root of 21035444 is about 276.0475483438.

Adding to 21035444 its reverse (44453012), we get a palindrome (65488456).

The spelling of 21035444 in words is "twenty-one million, thirty-five thousand, four hundred forty-four".