21224936 has 16 divisors (see below), whose sum is σ = 39852000. Its totient is φ = 10597744.

The previous prime is 21224933. The next prime is 21224941. The reversal of 21224936 is 63942212.

It is a junction number, because it is equal to n+sod(n) for n = 21224899 and 21224908.

It is not an unprimeable number, because it can be changed into a prime (21224933) 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, 6515 + ... + 9213.

It is an arithmetic number, because the mean of its divisors is an integer number (2490750).

Almost surely, 2^21224936 is an apocalyptic number.

It is an amenable number.

21224936 is a deficient number, since it is larger than the sum of its proper divisors (18627064).

21224936 is a wasteful number, since it uses less digits than its factorization.

21224936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3688 (or 3684 counting only the distinct ones).

The product of its digits is 5184, while the sum is 29.

The square root of 21224936 is about 4607.0528540489. The cubic root of 21224936 is about 276.8739711756.

The spelling of 21224936 in words is "twenty-one million, two hundred twenty-four thousand, nine hundred thirty-six".