21271611 has 16 divisors (see below), whose sum is σ = 29523968. Its totient is φ = 13608000.

The previous prime is 21271567. The next prime is 21271637. The reversal of 21271611 is 11617212.

It is a happy number.

It is not a de Polignac number, because 21271611 - 2⁷ = 21271483 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21272611) 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 15 ways as a sum of consecutive naturals, for example, 10911 + ... + 12711.

It is an arithmetic number, because the mean of its divisors is an integer number (1845248).

Almost surely, 2^21271611 is an apocalyptic number.

21271611 is a deficient number, since it is larger than the sum of its proper divisors (8252357).

21271611 is a wasteful number, since it uses less digits than its factorization.

21271611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1962.

The product of its digits is 168, while the sum is 21.

The square root of 21271611 is about 4612.1156750455. The cubic root of 21271611 is about 277.0767771465.

Adding to 21271611 its reverse (11617212), we get a palindrome (32888823).

The spelling of 21271611 in words is "twenty-one million, two hundred seventy-one thousand, six hundred eleven".