21621415563113 has 4 divisors (see below), whose sum is σ = 21643233339648. Its totient is φ = 21599597786580.

The previous prime is 21621415563109. The next prime is 21621415563169. The reversal of 21621415563113 is 31136551412612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21621415563113 - 2² = 21621415563109 is a prime.

It is a super-2 number, since 2×21621415563113² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21621415563413) 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, 10908886781 + ... + 10908888762.

It is an arithmetic number, because the mean of its divisors is an integer number (5410808334912).

Almost surely, 2^{21621415563113} is an apocalyptic number.

It is an amenable number.

21621415563113 is a deficient number, since it is larger than the sum of its proper divisors (21817776535).

21621415563113 is an equidigital number, since it uses as much as digits as its factorization.

21621415563113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21817776534.

The product of its digits is 129600, while the sum is 41.

Adding to 21621415563113 its reverse (31136551412612), we get a palindrome (52757966975725).

The spelling of 21621415563113 in words is "twenty-one trillion, six hundred twenty-one billion, four hundred fifteen million, five hundred sixty-three thousand, one hundred thirteen".