21313653629881 has 4 divisors (see below), whose sum is σ = 21313665226612. Its totient is φ = 21313642033152.

The previous prime is 21313653629867. The next prime is 21313653629899. The reversal of 21313653629881 is 18892635631312.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 15844252874256 + 5469400755625 = 3980484^2 + 2338675^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21313653629881 is a prime.

It is a super-2 number, since 2×21313653629881² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21313653629831) 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, 2363100 + ... + 6943453.

It is an arithmetic number, because the mean of its divisors is an integer number (5328416306653).

Almost surely, 2^{21313653629881} is an apocalyptic number.

It is an amenable number.

21313653629881 is a deficient number, since it is larger than the sum of its proper divisors (11596731).

21313653629881 is an equidigital number, since it uses as much as digits as its factorization.

21313653629881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11596730.

The product of its digits is 11197440, while the sum is 58.

The spelling of 21313653629881 in words is "twenty-one trillion, three hundred thirteen billion, six hundred fifty-three million, six hundred twenty-nine thousand, eight hundred eighty-one".