21161053 has 4 divisors (see below), whose sum is σ = 21459168. Its totient is φ = 20862940.

The previous prime is 21161051. The next prime is 21161059. The reversal of 21161053 is 35016112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21161053 - 2¹ = 21161051 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21161053.

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 polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 148951 + ... + 149092.

It is an arithmetic number, because the mean of its divisors is an integer number (5364792).

Almost surely, 2^21161053 is an apocalyptic number.

It is an amenable number.

21161053 is a deficient number, since it is larger than the sum of its proper divisors (298115).

21161053 is an equidigital number, since it uses as much as digits as its factorization.

21161053 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298114.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 21161053 is about 4600.1144550978. The cubic root of 21161053 is about 276.5959127792.

Adding to 21161053 its reverse (35016112), we get a palindrome (56177165).

The spelling of 21161053 in words is "twenty-one million, one hundred sixty-one thousand, fifty-three".