9947931839 has 2 divisors, whose sum is σ = 9947931840. Its totient is φ = 9947931838.

The previous prime is 9947931827. The next prime is 9947931853. The reversal of 9947931839 is 9381397499.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 9947931839 - 2⁸ = 9947931583 is a prime.

It is a super-2 number, since 2×9947931839² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9947961839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4973965919 + 4973965920.

It is an arithmetic number, because the mean of its divisors is an integer number (4973965920).

Almost surely, 2^9947931839 is an apocalyptic number.

9947931839 is a deficient number, since it is larger than the sum of its proper divisors (1).

9947931839 is an equidigital number, since it uses as much as digits as its factorization.

9947931839 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13226976, while the sum is 62.

The square root of 9947931839 is about 99739.3194231844. The cubic root of 9947931839 is about 2150.6889329236.

The spelling of 9947931839 in words is "nine billion, nine hundred forty-seven million, nine hundred thirty-one thousand, eight hundred thirty-nine".