21165113727 has 8 divisors (see below), whose sum is σ = 31355724080. Its totient is φ = 14110075800.

The previous prime is 21165113701. The next prime is 21165113731. The reversal of 21165113727 is 72731156112.

21165113727 is a `hidden beast` number, since 2 + 116 + 511 + 3 + 7 + 27 = 666.

It is not a de Polignac number, because 21165113727 - 2¹¹ = 21165111679 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21165113691 and 21165113700.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21165113777) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 391946524 + ... + 391946577.

It is an arithmetic number, because the mean of its divisors is an integer number (3919465510).

Almost surely, 2^21165113727 is an apocalyptic number.

21165113727 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

21165113727 is a deficient number, since it is larger than the sum of its proper divisors (10190610353).

21165113727 is an equidigital number, since it uses as much as digits as its factorization.

21165113727 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 783893110 (or 783893104 counting only the distinct ones).

The product of its digits is 17640, while the sum is 36.

Adding to 21165113727 its reverse (72731156112), we get a palindrome (93896269839).

The spelling of 21165113727 in words is "twenty-one billion, one hundred sixty-five million, one hundred thirteen thousand, seven hundred twenty-seven".