21033513 has 40 divisors (see below), whose sum is σ = 33686400. Its totient is φ = 13040352.

The previous prime is 21033479. The next prime is 21033517. The reversal of 21033513 is 31533012.

It is not a de Polignac number, because 21033513 - 2¹³ = 21025321 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21033517) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 121495 + ... + 121667.

It is an arithmetic number, because the mean of its divisors is an integer number (842160).

Almost surely, 2^21033513 is an apocalyptic number.

It is an amenable number.

21033513 is a deficient number, since it is larger than the sum of its proper divisors (12652887).

21033513 is a wasteful number, since it uses less digits than its factorization.

21033513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283 (or 274 counting only the distinct ones).

The product of its (nonzero) digits is 270, while the sum is 18.

The square root of 21033513 is about 4586.2308053564. The cubic root of 21033513 is about 276.0391012655.

Adding to 21033513 its reverse (31533012), we get a palindrome (52566525).

The spelling of 21033513 in words is "twenty-one million, thirty-three thousand, five hundred thirteen".