21503230513 has 8 divisors (see below), whose sum is σ = 21855004160. Its totient is φ = 21152363760.

The previous prime is 21503230501. The next prime is 21503230523. The reversal of 21503230513 is 31503230512.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21503230513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21503230523) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 178833 + ... + 273838.

It is an arithmetic number, because the mean of its divisors is an integer number (2731875520).

Almost surely, 2^21503230513 is an apocalyptic number.

It is an amenable number.

21503230513 is a deficient number, since it is larger than the sum of its proper divisors (351773647).

21503230513 is an equidigital number, since it uses as much as digits as its factorization.

21503230513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 453447.

The product of its (nonzero) digits is 2700, while the sum is 25.

Subtracting 21503230513 from its reverse (31503230512), we obtain a palindrome (9999999999).

The spelling of 21503230513 in words is "twenty-one billion, five hundred three million, two hundred thirty thousand, five hundred thirteen".