21152671 has 4 divisors (see below), whose sum is σ = 21551832. Its totient is φ = 20753512.

The previous prime is 21152669. The next prime is 21152683. The reversal of 21152671 is 17625112.

21152671 = T₁₉₄ + T₁₉₅ + ... + T₅₁₁.

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 21152671 - 2¹ = 21152669 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 (21150671) 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, 199501 + ... + 199606.

It is an arithmetic number, because the mean of its divisors is an integer number (5387958).

Almost surely, 2^21152671 is an apocalyptic number.

21152671 is a deficient number, since it is larger than the sum of its proper divisors (399161).

21152671 is an equidigital number, since it uses as much as digits as its factorization.

21152671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 399160.

The product of its digits is 840, while the sum is 25.

The square root of 21152671 is about 4599.2033005728. The cubic root of 21152671 is about 276.5593876101.

Adding to 21152671 its reverse (17625112), we get a palindrome (38777783).

The spelling of 21152671 in words is "twenty-one million, one hundred fifty-two thousand, six hundred seventy-one".