21272486665 has 32 divisors (see below), whose sum is σ = 27364552704. Its totient is φ = 15818987520.

The previous prime is 21272486647. The next prime is 21272486681. The reversal of 21272486665 is 56668427212.

It is not a de Polignac number, because 21272486665 - 2⁹ = 21272486153 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 2446125 + ... + 2454805.

It is an arithmetic number, because the mean of its divisors is an integer number (855142272).

Almost surely, 2^21272486665 is an apocalyptic number.

It is an amenable number.

21272486665 is a deficient number, since it is larger than the sum of its proper divisors (6092066039).

21272486665 is a wasteful number, since it uses less digits than its factorization.

21272486665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9057.

The product of its digits is 1935360, while the sum is 49.

The spelling of 21272486665 in words is "twenty-one billion, two hundred seventy-two million, four hundred eighty-six thousand, six hundred sixty-five".