21555054441 has 6 divisors (see below), whose sum is σ = 31135078650. Its totient is φ = 14370036288.

The previous prime is 21555054427. The next prime is 21555054467. The reversal of 21555054441 is 14445055512.

21555054441 is a `hidden beast` number, since 2 + 15 + 550 + 54 + 4 + 41 = 666.

It can be written as a sum of positive squares in only one way, i.e., 19992828816 + 1562225625 = 141396^2 + 39525^2 .

It is not a de Polignac number, because 21555054441 - 2⁶ = 21555054377 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21555054396 and 21555054405.

It is not an unprimeable number, because it can be changed into a prime (21555053441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1197503016 + ... + 1197503033.

It is an arithmetic number, because the mean of its divisors is an integer number (5189179775).

Almost surely, 2^21555054441 is an apocalyptic number.

It is an amenable number.

21555054441 is a deficient number, since it is larger than the sum of its proper divisors (9580024209).

21555054441 is a wasteful number, since it uses less digits than its factorization.

21555054441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2395006055 (or 2395006052 counting only the distinct ones).

The product of its (nonzero) digits is 80000, while the sum is 36.

The spelling of 21555054441 in words is "twenty-one billion, five hundred fifty-five million, fifty-four thousand, four hundred forty-one".