21105554446 has 32 divisors (see below), whose sum is σ = 33201799488. Its totient is φ = 10043066880.

The previous prime is 21105554389. The next prime is 21105554453. The reversal of 21105554446 is 64445550112.

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 9501616 + ... + 9503836.

It is an arithmetic number, because the mean of its divisors is an integer number (1037556234).

Almost surely, 2^21105554446 is an apocalyptic number.

21105554446 is a deficient number, since it is larger than the sum of its proper divisors (12096245042).

21105554446 is a wasteful number, since it uses less digits than its factorization.

21105554446 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3196.

The product of its (nonzero) digits is 96000, while the sum is 37.

It can be divided in two parts, 211055544 and 46, that multiplied together give a square (9708555024 = 98532²).

The spelling of 21105554446 in words is "twenty-one billion, one hundred five million, five hundred fifty-four thousand, four hundred forty-six".