21127011 has 4 divisors (see below), whose sum is σ = 28169352. Its totient is φ = 14084672.

The previous prime is 21127009. The next prime is 21127021. The reversal of 21127011 is 11072112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21127011 - 2¹ = 21127009 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21127021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3521166 + ... + 3521171.

It is an arithmetic number, because the mean of its divisors is an integer number (7042338).

Almost surely, 2^21127011 is an apocalyptic number.

21127011 is a deficient number, since it is larger than the sum of its proper divisors (7042341).

21127011 is an equidigital number, since it uses as much as digits as its factorization.

21127011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7042340.

The product of its (nonzero) digits is 28, while the sum is 15.

The square root of 21127011 is about 4596.4128404659. The cubic root of 21127011 is about 276.4475122921.

Adding to 21127011 its reverse (11072112), we get a palindrome (32199123).

The spelling of 21127011 in words is "twenty-one million, one hundred twenty-seven thousand, eleven".