7213616981 has 2 divisors, whose sum is σ = 7213616982. Its totient is φ = 7213616980.

The previous prime is 7213616959. The next prime is 7213616989. The reversal of 7213616981 is 1896163127.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3889517956 + 3324099025 = 62366^2 + 57655^2 .

It is a cyclic number.

It is not a de Polignac number, because 7213616981 - 2¹⁰ = 7213615957 is a prime.

It is a super-2 number, since 2×7213616981² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7213616989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3606808490 + 3606808491.

It is an arithmetic number, because the mean of its divisors is an integer number (3606808491).

Almost surely, 2^7213616981 is an apocalyptic number.

It is an amenable number.

7213616981 is a deficient number, since it is larger than the sum of its proper divisors (1).

7213616981 is an equidigital number, since it uses as much as digits as its factorization.

7213616981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108864, while the sum is 44.

The square root of 7213616981 is about 84933.0146703860. The cubic root of 7213616981 is about 1932.1953220997.

The spelling of 7213616981 in words is "seven billion, two hundred thirteen million, six hundred sixteen thousand, nine hundred eighty-one".