21001232613 has 16 divisors (see below), whose sum is σ = 28196349440. Its totient is φ = 13903778304.

The previous prime is 21001232521. The next prime is 21001232663. The reversal of 21001232613 is 31623210012.

It is not a de Polignac number, because 21001232613 - 2²⁴ = 20984455397 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21001232613.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001232663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 235245 + ... + 311997.

It is an arithmetic number, because the mean of its divisors is an integer number (1762271840).

Almost surely, 2^21001232613 is an apocalyptic number.

It is an amenable number.

21001232613 is a deficient number, since it is larger than the sum of its proper divisors (7195116827).

21001232613 is a wasteful number, since it uses less digits than its factorization.

21001232613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77388.

The product of its (nonzero) digits is 432, while the sum is 21.

Adding to 21001232613 its reverse (31623210012), we get a palindrome (52624442625).

The spelling of 21001232613 in words is "twenty-one billion, one million, two hundred thirty-two thousand, six hundred thirteen".