21221400021544 has 32 divisors (see below), whose sum is σ = 41178884551200. Its totient is φ = 10240660785600.

The previous prime is 21221400021517. The next prime is 21221400021599. The reversal of 21221400021544 is 44512000412212.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17966682 + ... + 19111369.

It is an arithmetic number, because the mean of its divisors is an integer number (1286840142225).

Almost surely, 2^{21221400021544} is an apocalyptic number.

It is an amenable number.

21221400021544 is a deficient number, since it is larger than the sum of its proper divisors (19957484529656).

21221400021544 is a wasteful number, since it uses less digits than its factorization.

21221400021544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37080553 (or 37080549 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 28.

Adding to 21221400021544 its reverse (44512000412212), we get a palindrome (65733400433756).

The spelling of 21221400021544 in words is "twenty-one trillion, two hundred twenty-one billion, four hundred million, twenty-one thousand, five hundred forty-four".