9981961807 has 2 divisors, whose sum is σ = 9981961808. Its totient is φ = 9981961806.

The previous prime is 9981961799. The next prime is 9981961867. The reversal of 9981961807 is 7081691899.

It is a weak prime.

It is an emirp because it is prime and its reverse (7081691899) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9981961807 - 2³ = 9981961799 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9981961867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4990980903 + 4990980904.

It is an arithmetic number, because the mean of its divisors is an integer number (4990980904).

Almost surely, 2^9981961807 is an apocalyptic number.

9981961807 is a deficient number, since it is larger than the sum of its proper divisors (1).

9981961807 is an equidigital number, since it uses as much as digits as its factorization.

9981961807 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1959552, while the sum is 58.

The square root of 9981961807 is about 99909.7683262252. The cubic root of 9981961807 is about 2153.1385067342.

The spelling of 9981961807 in words is "nine billion, nine hundred eighty-one million, nine hundred sixty-one thousand, eight hundred seven".