21544919712 has 36 divisors (see below), whose sum is σ = 61268366250. Its totient is φ = 7181639808.

The previous prime is 21544919681. The next prime is 21544919819. The reversal of 21544919712 is 21791944512.

21544919712 is a `hidden beast` number, since 2 + 1 + 5 + 449 + 197 + 12 = 666.

It can be written as a sum of positive squares in only one way, i.e., 21107440656 + 437479056 = 145284^2 + 20916^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 37404087 + ... + 37404662.

Almost surely, 2^21544919712 is an apocalyptic number.

It is an amenable number.

21544919712 is an abundant number, since it is smaller than the sum of its proper divisors (39723446538).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21544919712 is a wasteful number, since it uses less digits than its factorization.

21544919712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74808765 (or 74808754 counting only the distinct ones).

The product of its digits is 181440, while the sum is 45.

The spelling of 21544919712 in words is "twenty-one billion, five hundred forty-four million, nine hundred nineteen thousand, seven hundred twelve".