21444101521521 has 48 divisors (see below), whose sum is σ = 33356195383680. Its totient is φ = 12218426814720.

The previous prime is 21444101521471. The next prime is 21444101521543. The reversal of 21444101521521 is 12512510144412.

It is not a de Polignac number, because 21444101521521 - 2⁹ = 21444101521009 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21444101521421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1053391675 + ... + 1053412031.

It is an arithmetic number, because the mean of its divisors is an integer number (694920737160).

Almost surely, 2^{21444101521521} is an apocalyptic number.

21444101521521 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21444101521521 is a deficient number, since it is larger than the sum of its proper divisors (11912093862159).

21444101521521 is a wasteful number, since it uses less digits than its factorization.

21444101521521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40694 (or 40687 counting only the distinct ones).

The product of its (nonzero) digits is 12800, while the sum is 33.

Adding to 21444101521521 its reverse (12512510144412), we get a palindrome (33956611665933).

The spelling of 21444101521521 in words is "twenty-one trillion, four hundred forty-four billion, one hundred one million, five hundred twenty-one thousand, five hundred twenty-one".