21004352 has 28 divisors (see below), whose sum is σ = 43121580. Its totient is φ = 10139136.

The previous prime is 21004351. The next prime is 21004387. The reversal of 21004352 is 25340012.

It can be written as a sum of positive squares in 2 ways, for example, as 16777216 + 4227136 = 4096^2 + 2056^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21004352.

It is not an unprimeable number, because it can be changed into a prime (21004351) 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, 3803 + ... + 7514.

Almost surely, 2^21004352 is an apocalyptic number.

It is an amenable number.

21004352 is an abundant number, since it is smaller than the sum of its proper divisors (22117228).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21004352 is a wasteful number, since it uses less digits than its factorization.

21004352 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11358 (or 11348 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 21004352 is about 4583.0505124862. The cubic root of 21004352 is about 275.9114747948.

Adding to 21004352 its reverse (25340012), we get a palindrome (46344364).

The spelling of 21004352 in words is "twenty-one million, four thousand, three hundred fifty-two".