21513236383 has 4 divisors (see below), whose sum is σ = 21581101800. Its totient is φ = 21445370968.

The previous prime is 21513236341. The next prime is 21513236411. The reversal of 21513236383 is 38363231512.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21513236383 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21513236333) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33932233 + ... + 33932866.

It is an arithmetic number, because the mean of its divisors is an integer number (5395275450).

Almost surely, 2^21513236383 is an apocalyptic number.

21513236383 is a deficient number, since it is larger than the sum of its proper divisors (67865417).

21513236383 is an equidigital number, since it uses as much as digits as its factorization.

21513236383 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67865416.

The product of its digits is 77760, while the sum is 37.

Adding to 21513236383 its reverse (38363231512), we get a palindrome (59876467895).

The spelling of 21513236383 in words is "twenty-one billion, five hundred thirteen million, two hundred thirty-six thousand, three hundred eighty-three".