213947861 has 2 divisors, whose sum is σ = 213947862. Its totient is φ = 213947860.

The previous prime is 213947857. The next prime is 213947893. The reversal of 213947861 is 168749312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 125305636 + 88642225 = 11194^2 + 9415^2 .

It is a cyclic number.

It is not a de Polignac number, because 213947861 - 2² = 213947857 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 (213946861) 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, 106973930 + 106973931.

It is an arithmetic number, because the mean of its divisors is an integer number (106973931).

Almost surely, 2^213947861 is an apocalyptic number.

It is an amenable number.

213947861 is a deficient number, since it is larger than the sum of its proper divisors (1).

213947861 is an equidigital number, since it uses as much as digits as its factorization.

213947861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72576, while the sum is 41.

The square root of 213947861 is about 14626.9566554359. The cubic root of 213947861 is about 598.0938218508.

The spelling of 213947861 in words is "two hundred thirteen million, nine hundred forty-seven thousand, eight hundred sixty-one".