21204102513 has 8 divisors (see below), whose sum is σ = 30842330976. Its totient is φ = 12850971200.

The previous prime is 21204102511. The next prime is 21204102539. The reversal of 21204102513 is 31520140212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21204102513 - 2¹ = 21204102511 is a prime.

It is a super-2 number, since 2×21204102513² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21204102513.

It is not an unprimeable number, because it can be changed into a prime (21204102511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 321274248 + ... + 321274313.

It is an arithmetic number, because the mean of its divisors is an integer number (3855291372).

Almost surely, 2^21204102513 is an apocalyptic number.

It is an amenable number.

21204102513 is a deficient number, since it is larger than the sum of its proper divisors (9638228463).

21204102513 is a wasteful number, since it uses less digits than its factorization.

21204102513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 642548575.

The product of its (nonzero) digits is 480, while the sum is 21.

Adding to 21204102513 its reverse (31520140212), we get a palindrome (52724242725).

The spelling of 21204102513 in words is "twenty-one billion, two hundred four million, one hundred two thousand, five hundred thirteen".