21445124 has 12 divisors (see below), whose sum is σ = 38058048. Its totient is φ = 10571400.

The previous prime is 21445121. The next prime is 21445133. The reversal of 21445124 is 42154412.

It is a self number, because there is not a number n which added to its sum of digits gives 21445124.

It is not an unprimeable number, because it can be changed into a prime (21445121) 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, 37472 + ... + 38039.

It is an arithmetic number, because the mean of its divisors is an integer number (3171504).

Almost surely, 2^21445124 is an apocalyptic number.

It is an amenable number.

21445124 is a deficient number, since it is larger than the sum of its proper divisors (16612924).

21445124 is a wasteful number, since it uses less digits than its factorization.

21445124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75586 (or 75584 counting only the distinct ones).

The product of its digits is 1280, while the sum is 23.

The square root of 21445124 is about 4630.8880357875. Note that the first 3 decimals coincide. The cubic root of 21445124 is about 277.8281117440.

Adding to 21445124 its reverse (42154412), we get a palindrome (63599536).

The spelling of 21445124 in words is "twenty-one million, four hundred forty-five thousand, one hundred twenty-four".