395939721869 has 2 divisors, whose sum is σ = 395939721870. Its totient is φ = 395939721868.

The previous prime is 395939721743. The next prime is 395939721901. The reversal of 395939721869 is 968127939593.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 306904920100 + 89034801769 = 553990^2 + 298387^2 .

It is a cyclic number.

It is not a de Polignac number, because 395939721869 - 2¹² = 395939717773 is a prime.

It is a super-2 number, since 2×395939721869² (a number of 24 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 (395939721469) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 197969860934 + 197969860935.

It is an arithmetic number, because the mean of its divisors is an integer number (197969860935).

Almost surely, 2^395939721869 is an apocalyptic number.

It is an amenable number.

395939721869 is a deficient number, since it is larger than the sum of its proper divisors (1).

395939721869 is an equidigital number, since it uses as much as digits as its factorization.

395939721869 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 198404640, while the sum is 71.

The spelling of 395939721869 in words is "three hundred ninety-five billion, nine hundred thirty-nine million, seven hundred twenty-one thousand, eight hundred sixty-nine".