21335144 has 16 divisors (see below), whose sum is σ = 40064100. Its totient is φ = 10651392.

The previous prime is 21335143. The next prime is 21335173. The reversal of 21335144 is 44153312.

It can be written as a sum of positive squares in 2 ways, for example, as 19802500 + 1532644 = 4450^2 + 1238^2 .

It is not an unprimeable number, because it can be changed into a prime (21335141) 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, 5024 + ... + 8240.

Almost surely, 2^21335144 is an apocalyptic number.

It is an amenable number.

21335144 is a deficient number, since it is larger than the sum of its proper divisors (18728956).

21335144 is a wasteful number, since it uses less digits than its factorization.

21335144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4052 (or 4048 counting only the distinct ones).

The product of its digits is 1440, while the sum is 23.

The square root of 21335144 is about 4618.9981597745. The cubic root of 21335144 is about 277.3523560567.

Adding to 21335144 its reverse (44153312), we get a palindrome (65488456).

The spelling of 21335144 in words is "twenty-one million, three hundred thirty-five thousand, one hundred forty-four".