213409997 has 2 divisors, whose sum is σ = 213409998. Its totient is φ = 213409996.

The previous prime is 213409981. The next prime is 213410009. The reversal of 213409997 is 799904312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 111218116 + 102191881 = 10546^2 + 10109^2 .

It is a cyclic number.

It is not a de Polignac number, because 213409997 - 2⁴ = 213409981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213409907) 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, 106704998 + 106704999.

It is an arithmetic number, because the mean of its divisors is an integer number (106704999).

Almost surely, 2^213409997 is an apocalyptic number.

It is an amenable number.

213409997 is a deficient number, since it is larger than the sum of its proper divisors (1).

213409997 is an equidigital number, since it uses as much as digits as its factorization.

213409997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 122472, while the sum is 44.

The square root of 213409997 is about 14608.5590322934. The cubic root of 213409997 is about 597.5921994938.

The spelling of 213409997 in words is "two hundred thirteen million, four hundred nine thousand, nine hundred ninety-seven".