21052011 has 16 divisors (see below), whose sum is σ = 28512000. Its totient is φ = 13815648.

The previous prime is 21051991. The next prime is 21052039. The reversal of 21052011 is 11025012.

21052011 = T₁₄₈ + T₁₄₉ + ... + T₅₀₅.

It is not a de Polignac number, because 21052011 - 2¹⁰ = 21050987 is a prime.

It is a super-3 number, since 3×21052011³ (a number of 23 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21052051) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 105690 + ... + 105888.

It is an arithmetic number, because the mean of its divisors is an integer number (1782000).

Almost surely, 2^21052011 is an apocalyptic number.

21052011 is a deficient number, since it is larger than the sum of its proper divisors (7459989).

21052011 is a wasteful number, since it uses less digits than its factorization.

21052011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 578.

The product of its (nonzero) digits is 20, while the sum is 12.

The square root of 21052011 is about 4588.2470508899. The cubic root of 21052011 is about 276.1199987543.

Adding to 21052011 its reverse (11025012), we get a palindrome (32077023).

The spelling of 21052011 in words is "twenty-one million, fifty-two thousand, eleven".