21226536505145 has 4 divisors (see below), whose sum is σ = 25471843806180. Its totient is φ = 16981229204112.

The previous prime is 21226536505117. The next prime is 21226536505177. The reversal of 21226536505145 is 54150563562212.

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 11572161596944 + 9654374908201 = 3401788^2 + 3107149^2 .

It is a cyclic number.

It is not a de Polignac number, because 21226536505145 - 2⁸ = 21226536504889 is a prime.

It is a super-2 number, since 2×21226536505145² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21226536505145.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2122653650510 + ... + 2122653650519.

It is an arithmetic number, because the mean of its divisors is an integer number (6367960951545).

Almost surely, 2^{21226536505145} is an apocalyptic number.

It is an amenable number.

21226536505145 is a deficient number, since it is larger than the sum of its proper divisors (4245307301035).

21226536505145 is an equidigital number, since it uses as much as digits as its factorization.

21226536505145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4245307301034.

The product of its (nonzero) digits is 2160000, while the sum is 47.

The spelling of 21226536505145 in words is "twenty-one trillion, two hundred twenty-six billion, five hundred thirty-six million, five hundred five thousand, one hundred forty-five".