21161727 has 6 divisors (see below), whose sum is σ = 30566952. Its totient is φ = 14107812.

The previous prime is 21161717. The next prime is 21161729. The reversal of 21161727 is 72716112.

21161727 is a `hidden beast` number, since 21 + 1 + 617 + 27 = 666.

It is not a de Polignac number, because 21161727 - 2¹⁴ = 21145343 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21161727.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21161729) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1175643 + ... + 1175660.

It is an arithmetic number, because the mean of its divisors is an integer number (5094492).

Almost surely, 2^21161727 is an apocalyptic number.

21161727 is a deficient number, since it is larger than the sum of its proper divisors (9405225).

21161727 is a wasteful number, since it uses less digits than its factorization.

21161727 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2351309 (or 2351306 counting only the distinct ones).

The product of its digits is 1176, while the sum is 27.

The square root of 21161727 is about 4600.1877135613. The cubic root of 21161727 is about 276.5988493638.

Adding to 21161727 its reverse (72716112), we get a palindrome (93877839).

The spelling of 21161727 in words is "twenty-one million, one hundred sixty-one thousand, seven hundred twenty-seven".