21310871 has 2 divisors, whose sum is σ = 21310872. Its totient is φ = 21310870.

The previous prime is 21310847. The next prime is 21310889. The reversal of 21310871 is 17801312.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21310871 - 2¹⁴ = 21294487 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21310801) 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 as a sum of consecutive naturals, namely, 10655435 + 10655436.

It is an arithmetic number, because the mean of its divisors is an integer number (10655436).

Almost surely, 2^21310871 is an apocalyptic number.

21310871 is a deficient number, since it is larger than the sum of its proper divisors (1).

21310871 is an equidigital number, since it uses as much as digits as its factorization.

21310871 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 336, while the sum is 23.

The square root of 21310871 is about 4616.3698941918. The cubic root of 21310871 is about 277.2471348558.

The spelling of 21310871 in words is "twenty-one million, three hundred ten thousand, eight hundred seventy-one".