21109563649273 has 12 divisors (see below), whose sum is σ = 23235800667940. Its totient is φ = 19163445317280.

The previous prime is 21109563649261. The next prime is 21109563649327. The reversal of 21109563649273 is 37294636590112.

It can be written as a sum of positive squares in 2 ways, for example, as 802391352169 + 20307172297104 = 895763^2 + 4506348^2 .

It is not a de Polignac number, because 21109563649273 - 2⁵ = 21109563649241 is a prime.

It is a super-2 number, since 2×21109563649273² (a number of 27 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (58) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21109563649073) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 122946090 + ... + 123117667.

Almost surely, 2^{21109563649273} is an apocalyptic number.

It is an amenable number.

21109563649273 is a deficient number, since it is larger than the sum of its proper divisors (2126237018667).

21109563649273 is a wasteful number, since it uses less digits than its factorization.

21109563649273 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246064488 (or 246064477 counting only the distinct ones).

The product of its (nonzero) digits is 14696640, while the sum is 58.

The spelling of 21109563649273 in words is "twenty-one trillion, one hundred nine billion, five hundred sixty-three million, six hundred forty-nine thousand, two hundred seventy-three".