213621971 has 2 divisors, whose sum is σ = 213621972. Its totient is φ = 213621970.

The previous prime is 213621913. The next prime is 213621973. The reversal of 213621971 is 179126312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 213621971 - 2²² = 209427667 is a prime.

Together with 213621973, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (213621973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106810985 + 106810986.

It is an arithmetic number, because the mean of its divisors is an integer number (106810986).

Almost surely, 2^213621971 is an apocalyptic number.

213621971 is a deficient number, since it is larger than the sum of its proper divisors (1).

213621971 is an equidigital number, since it uses as much as digits as its factorization.

213621971 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4536, while the sum is 32.

The square root of 213621971 is about 14615.8123619592. The cubic root of 213621971 is about 597.7899910582.

The spelling of 213621971 in words is "two hundred thirteen million, six hundred twenty-one thousand, nine hundred seventy-one".