7213861 has 2 divisors, whose sum is σ = 7213862. Its totient is φ = 7213860.

The previous prime is 7213859. The next prime is 7213897. The reversal of 7213861 is 1683127.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7049025 + 164836 = 2655^2 + 406^2 .

It is a cyclic number.

It is not a de Polignac number, because 7213861 - 2¹ = 7213859 is a prime.

Together with 7213859, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7213841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3606930 + 3606931.

It is an arithmetic number, because the mean of its divisors is an integer number (3606931).

Almost surely, 2^7213861 is an apocalyptic number.

It is an amenable number.

7213861 is a deficient number, since it is larger than the sum of its proper divisors (1).

7213861 is an equidigital number, since it uses as much as digits as its factorization.

7213861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2016, while the sum is 28.

The square root of 7213861 is about 2685.8631759641. The cubic root of 7213861 is about 193.2217109000.

Adding to 7213861 its reverse (1683127), we get a palindrome (8896988).

The spelling of 7213861 in words is "seven million, two hundred thirteen thousand, eight hundred sixty-one".