21024272 has 10 divisors (see below), whose sum is σ = 40734558. Its totient is φ = 10512128.

The previous prime is 21024271. The next prime is 21024299. The reversal of 21024272 is 27242012.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 16289296 + 4734976 = 4036^2 + 2176^2 .

It is not an unprimeable number, because it can be changed into a prime (21024271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 656993 + ... + 657024.

Almost surely, 2^21024272 is an apocalyptic number.

It is an amenable number.

21024272 is a deficient number, since it is larger than the sum of its proper divisors (19710286).

21024272 is a wasteful number, since it uses less digits than its factorization.

21024272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1314025 (or 1314019 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 20.

The square root of 21024272 is about 4585.2232224833. The cubic root of 21024272 is about 275.9986697408.

Adding to 21024272 its reverse (27242012), we get a palindrome (48266284).

The spelling of 21024272 in words is "twenty-one million, twenty-four thousand, two hundred seventy-two".