213121871 has 2 divisors, whose sum is σ = 213121872. Its totient is φ = 213121870.

The previous prime is 213121859. The next prime is 213121873. The reversal of 213121871 is 178121312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 213121871 - 2¹⁸ = 212859727 is a prime.

Together with 213121873, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 213121871.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213121873) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106560935 + 106560936.

It is an arithmetic number, because the mean of its divisors is an integer number (106560936).

Almost surely, 2^213121871 is an apocalyptic number.

213121871 is a deficient number, since it is larger than the sum of its proper divisors (1).

213121871 is an equidigital number, since it uses as much as digits as its factorization.

213121871 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 672, while the sum is 26.

The square root of 213121871 is about 14598.6941539303. The cubic root of 213121871 is about 597.3231408765.

The spelling of 213121871 in words is "two hundred thirteen million, one hundred twenty-one thousand, eight hundred seventy-one".