6961881989 has 2 divisors, whose sum is σ = 6961881990. Its totient is φ = 6961881988.

The previous prime is 6961881931. The next prime is 6961881991. The reversal of 6961881989 is 9891881696.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3521472964 + 3440409025 = 59342^2 + 58655^2 .

It is a cyclic number.

It is not a de Polignac number, because 6961881989 - 2²⁴ = 6945104773 is a prime.

It is a super-2 number, since 2×6961881989² = 96935601657525192242, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 6961881991, it forms a pair of twin primes.

It is a Chen 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 (6961281989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3480940994 + 3480940995.

It is an arithmetic number, because the mean of its divisors is an integer number (3480940995).

Almost surely, 2^6961881989 is an apocalyptic number.

It is an amenable number.

6961881989 is a deficient number, since it is larger than the sum of its proper divisors (1).

6961881989 is an equidigital number, since it uses as much as digits as its factorization.

6961881989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13436928, while the sum is 65.

The square root of 6961881989 is about 83437.8930043179. The cubic root of 6961881989 is about 1909.4526166399.

The spelling of 6961881989 in words is "six billion, nine hundred sixty-one million, eight hundred eighty-one thousand, nine hundred eighty-nine".