21011130644653 has 4 divisors (see below), whose sum is σ = 21298954352188. Its totient is φ = 20723306937120.

The previous prime is 21011130644641. The next prime is 21011130644663. The reversal of 21011130644653 is 35644603111012.

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

It can be written as a sum of positive squares in 2 ways, for example, as 8301071420964 + 12710059223689 = 2881158^2 + 3565117^2 .

It is a cyclic number.

It is not a de Polignac number, because 21011130644653 - 2³³ = 21002540710061 is a prime.

It is a super-2 number, since 2×21011130644653² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011130644663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 143911853658 + ... + 143911853803.

It is an arithmetic number, because the mean of its divisors is an integer number (5324738588047).

Almost surely, 2^{21011130644653} is an apocalyptic number.

It is an amenable number.

21011130644653 is a deficient number, since it is larger than the sum of its proper divisors (287823707535).

21011130644653 is an equidigital number, since it uses as much as digits as its factorization.

21011130644653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 287823707534.

The product of its (nonzero) digits is 51840, while the sum is 37.

Adding to 21011130644653 its reverse (35644603111012), we get a palindrome (56655733755665).

The spelling of 21011130644653 in words is "twenty-one trillion, eleven billion, one hundred thirty million, six hundred forty-four thousand, six hundred fifty-three".