21004203353 has 32 divisors (see below), whose sum is σ = 25658572800. Its totient is φ = 16793951616.

The previous prime is 21004203331. The next prime is 21004203371. The reversal of 21004203353 is 35330240012.

It is a cyclic number.

It is not a de Polignac number, because 21004203353 - 2³⁴ = 3824334169 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21004209353) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3452168 + ... + 3458246.

It is an arithmetic number, because the mean of its divisors is an integer number (801830400).

Almost surely, 2^21004203353 is an apocalyptic number.

It is an amenable number.

21004203353 is a deficient number, since it is larger than the sum of its proper divisors (4654369447).

21004203353 is a wasteful number, since it uses less digits than its factorization.

21004203353 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6501.

The product of its (nonzero) digits is 2160, while the sum is 23.

Adding to 21004203353 its reverse (35330240012), we get a palindrome (56334443365).

The spelling of 21004203353 in words is "twenty-one billion, four million, two hundred three thousand, three hundred fifty-three".