21161061 has 8 divisors (see below), whose sum is σ = 31349760. Its totient is φ = 14107356.

The previous prime is 21161059. The next prime is 21161089. The reversal of 21161061 is 16016112.

It is not a de Polignac number, because 21161061 - 2¹ = 21161059 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21161051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 391845 + ... + 391898.

It is an arithmetic number, because the mean of its divisors is an integer number (3918720).

Almost surely, 2^21161061 is an apocalyptic number.

It is an amenable number.

21161061 is a deficient number, since it is larger than the sum of its proper divisors (10188699).

21161061 is an equidigital number, since it uses as much as digits as its factorization.

21161061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 783752 (or 783746 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 21161061 is about 4600.1153246413. The cubic root of 21161061 is about 276.5959476352.

Adding to 21161061 its reverse (16016112), we get a palindrome (37177173).

The spelling of 21161061 in words is "twenty-one million, one hundred sixty-one thousand, sixty-one".