21140671 has 4 divisors (see below), whose sum is σ = 21151144. Its totient is φ = 21130200.

The previous prime is 21140663. The next prime is 21140677. The reversal of 21140671 is 17604112.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21140671 - 2³ = 21140663 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21140677) 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, 1140 + ... + 6601.

It is an arithmetic number, because the mean of its divisors is an integer number (5287786).

Almost surely, 2^21140671 is an apocalyptic number.

21140671 is a deficient number, since it is larger than the sum of its proper divisors (10473).

21140671 is an equidigital number, since it uses as much as digits as its factorization.

21140671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10472.

The product of its (nonzero) digits is 336, while the sum is 22.

The square root of 21140671 is about 4597.8985417253. The cubic root of 21140671 is about 276.5070799461.

Adding to 21140671 its reverse (17604112), we get a palindrome (38744783).

The spelling of 21140671 in words is "twenty-one million, one hundred forty thousand, six hundred seventy-one".