21765654005 has 4 divisors (see below), whose sum is σ = 26118784812. Its totient is φ = 17412523200.

The previous prime is 21765653999. The next prime is 21765654007. The reversal of 21765654005 is 50045656712.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8555140036 + 13210513969 = 92494^2 + 114937^2 .

It is not a de Polignac number, because 21765654005 - 2¹⁰ = 21765652981 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21765654007) 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 3 ways as a sum of consecutive naturals, for example, 2176565396 + ... + 2176565405.

It is an arithmetic number, because the mean of its divisors is an integer number (6529696203).

Almost surely, 2^21765654005 is an apocalyptic number.

It is an amenable number.

21765654005 is a deficient number, since it is larger than the sum of its proper divisors (4353130807).

21765654005 is an equidigital number, since it uses as much as digits as its factorization.

21765654005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4353130806.

The product of its (nonzero) digits is 252000, while the sum is 41.

The spelling of 21765654005 in words is "twenty-one billion, seven hundred sixty-five million, six hundred fifty-four thousand, five".