21244534021055 has 4 divisors (see below), whose sum is σ = 25493440825272. Its totient is φ = 16995627216840.

The previous prime is 21244534021001. The next prime is 21244534021069. The reversal of 21244534021055 is 55012043544212.

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

It is not a de Polignac number, because 21244534021055 - 2⁸ = 21244534020799 is a prime.

It is a Duffinian number.

It is a congruent number.

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, 2124453402101 + ... + 2124453402110.

It is an arithmetic number, because the mean of its divisors is an integer number (6373360206318).

Almost surely, 2^{21244534021055} is an apocalyptic number.

21244534021055 is a deficient number, since it is larger than the sum of its proper divisors (4248906804217).

21244534021055 is an equidigital number, since it uses as much as digits as its factorization.

21244534021055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4248906804216.

The product of its (nonzero) digits is 192000, while the sum is 38.

Adding to 21244534021055 its reverse (55012043544212), we get a palindrome (76256577565267).

The spelling of 21244534021055 in words is "twenty-one trillion, two hundred forty-four billion, five hundred thirty-four million, twenty-one thousand, fifty-five".