21215296 has 14 divisors (see below), whose sum is σ = 42099230. Its totient is φ = 10607616.

The previous prime is 21215291. The next prime is 21215309. The reversal of 21215296 is 69251212.

It can be written as a sum of positive squares in only one way, i.e., 20575296 + 640000 = 4536^2 + 800^2 .

It is not an unprimeable number, because it can be changed into a prime (21215291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165681 + ... + 165808.

Almost surely, 2^21215296 is an apocalyptic number.

It is an amenable number.

21215296 is a deficient number, since it is larger than the sum of its proper divisors (20883934).

21215296 is an equidigital number, since it uses as much as digits as its factorization.

21215296 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 331501 (or 331491 counting only the distinct ones).

The product of its digits is 2160, while the sum is 28.

The square root of 21215296 is about 4606.0065132390. The cubic root of 21215296 is about 276.8320477000.

The spelling of 21215296 in words is "twenty-one million, two hundred fifteen thousand, two hundred ninety-six".