21615566222363 has 2 divisors, whose sum is σ = 21615566222364. Its totient is φ = 21615566222362.

The previous prime is 21615566222347. The next prime is 21615566222417. The reversal of 21615566222363 is 36322266551612.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21615566222363 - 2⁴ = 21615566222347 is a prime.

It is a super-2 number, since 2×21615566222363² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21615566222303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10807783111181 + 10807783111182.

It is an arithmetic number, because the mean of its divisors is an integer number (10807783111182).

Almost surely, 2^{21615566222363} is an apocalyptic number.

21615566222363 is a deficient number, since it is larger than the sum of its proper divisors (1).

21615566222363 is an equidigital number, since it uses as much as digits as its factorization.

21615566222363 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4665600, while the sum is 50.

The spelling of 21615566222363 in words is "twenty-one trillion, six hundred fifteen billion, five hundred sixty-six million, two hundred twenty-two thousand, three hundred sixty-three".